Oct/Nov 2014

A $0.10\,\text{kg}$ mass is transported to Mars, where it is measured using a spring balance and a lever balance. The acceleration due to gravity on Mars is $38\%$ of its value on Earth. What are the readings on the two balances on Mars? (Assume that on Earth $g = 10\,\text{m s}^{-2}$.)

Equilibrium of forces

A glider moves downwards at steady speed at an angle of $15^{\circ}$ to the horizontal. The diagram indicates the directions of the lift $L$, air resistance $R$ and weight $W$ acting on the glider. Which vector triangle could represent the forces acting on the glider?

Equilibrium of forces

A ball is descending at terminal speed in still air. The forces acting on the ball are upthrust, viscous drag and weight. In what order do these three forces increase in magnitude?

Equilibrium of forces

A uniform ladder is leaning against a vertical wall with negligible friction. Its lower end is on rough ground, so friction acts at the base. The top of the ladder is at a height $h$ above the ground, and the foot of the ladder is $2a$ from the wall. The diagram shows the forces acting on the ladder. Which equation results from taking moments?

Turning effects of forces

A mass fixed to the bottom end of a spring oscillates vertically. At which positions in the mass’s motion do the gravitational potential energy of the mass (GPE), the elastic potential energy stored in the spring (EPE) and the kinetic energy of the mass (KE) each reach their maximum values?

Energy conservation

A mass $m$ is located within a uniform gravitational field. As the mass undergoes a displacement $x$, from P to Q, it loses potential energy $E$. Which row correctly states the magnitude and the direction of the acceleration due to gravity in this field?

Gravitational potential energy and kinetic energy

A small electric motor is fixed on a bench, as illustrated. It is supplied with $6.0\text{ V}$ and the current in the motor is $0.50\text{ A}$. The motor has an efficiency of 50%. What time is needed to raise a mass of $200\text{ g}$ through a height of $90\text{ cm}$?

Potential difference and power

A projectile is fired at $45^\circ$ above the horizontal with initial kinetic energy $E$. If air resistance is taken to be negligible, what is the kinetic energy of the projectile at its maximum height?

Gravitational potential energy and kinetic energy

What name is given to a substance made of long-chain molecules that are tangled and coiled?

Elastic and plastic behaviour

Which statement concerning molecules in a gas is correct?

Density and pressure

The diagram represents the atoms in a substance, with the atoms located at the corners of a cube. At a certain temperature, the average distance between the atoms is $15\text{ nm}$. If the temperature alters so that the average distance becomes $17\text{ nm}$, by which factor does the density of the substance change?

Density and pressure

What does the unit of electric field strength equal?

Potential difference and power

The stress-strain graph for a glass rod, shown here up to the point where it fractures, is below. Which statement correctly describes the glass rod?

Elastic and plastic behaviour

A rubber band is extended by suspending weights from it, and the results are used to draw a force-extension graph. What is the most suitable estimate of the strain energy stored in the rubber band when its extension is $30\,\text{cm}$?

Elastic and plastic behaviour

Which statement concerning electromagnetic radiation is correct?

Electromagnetic spectrum

As sound propagates through air, the air particles oscillate. A displacement-time graph for one air particle is shown. Which graph most accurately represents how the kinetic energy of the air particle changes with time?

Progressive waves

Which statement describes a situation in which polarisation could not take place?

Polarisation

Inside a tube, a stationary sound wave is created. Which statement gives the wave speed?

Stationary waves

As illustrated, two identical loudspeakers are joined in series to an a.c. supply. Which graph most accurately shows how the intensity of the sound changes with distance along the line $XY$?

Interference

An experiment using a diffraction grating is arranged with yellow light of wavelength $600\,\text{nm}$. The grating has a slit separation of $2.00\,\mu\text{m}$. What is the angular separation $(\theta_2-\theta_1)$ between the first-order and second-order maxima for the yellow light?

The diffraction grating

The diagram depicts two horizontal metal plates that are parallel to each other. A potential difference $V$ exists across the plates. A tiny charged liquid drop is positioned halfway between the plates and remains in equilibrium because its weight is balanced by the electric force on it. The acceleration of free fall is $g$ and the electric field strength is $E$. Determine the polarity of the charge on the drop, and find the ratio of charge to mass of the drop.

Equilibrium of forces

The diagram illustrates two metal plates joined to a constant high voltage. Which graph shows how the electric field strength $E$ at the midpoint between the two plates changes as the distance $d$ separating the plates is increased?

Potential difference and power

The diagram illustrates the reading shown on an analogue ammeter. Which digital ammeter reading is equal to the reading on the analogue ammeter?

Practical circuits

$B_1$, $B_2$ and $B_3$ are three lamps that are identical. They are connected to a battery with zero internal resistance, as illustrated. At first, the switch is closed. The switch is then opened and lamp $B_3$ goes out. What change occurs in the brightness of lamps $B_1$ and $B_2$ when the switch is opened?

Practical circuits

A battery is labelled $9.0\,\text{V}$. What is meant by this?

Potential difference and power

Using a pencil, a line with length $30\ \text{cm}$ and width $1.2\ \text{mm}$ is made. The resistivity of the pencil material is $2.0 \times 10^{-5}\ \Omega\,\text{m}$, and the resistance of the line is $40\ \text{k}\Omega$. What is the thickness of the line?

Resistance and resistivity

A conductor is formed from three wires joined one after another in series. Each wire is made from the same metal, but their cross-sectional areas are different. A current $I$ flows through the conductor. Point $Y$ on the conductor is at zero potential. Which graph most accurately represents how potential $V$ changes with distance along the conductor?

Potential difference and power

The graph illustrates the way the electric current $I$ in a conducting liquid changes with the potential difference $V$ across it. At which point on the graph is the liquid's resistance the smallest?

Resistance and resistivity

For two resistors with resistances $R_1$ and $R_2$ connected in parallel, the total resistance $R_T$ is given by the formula shown below. $$\frac{1}{R_T} = \frac{1}{R_1} + \frac{1}{R_2}$$ Which statement is used to derive this formula?

Kirchhoff's laws

For the potentiometer circuit shown, the ammeter first has a zero reading. Next, the light-dependent resistor (LDR) is covered, causing the ammeter to show a non-zero reading. Which change could bring the ammeter reading back to zero?

Potential dividers

Six resistors, each with resistance $R$, are arranged as illustrated. Their total resistance is $66\,\text{k}\Omega$. Determine the value of $R$.

Resistance and resistivity

Which statement concerning $\alpha$-particles is correct?

Atoms, nuclei and radiation

The isotope $^{222}_{86}\text{Rn}$ undergoes a chain of emissions to produce the isotope $^{206}_{82}\text{Pb}$. At each point in the decay chain, it releases either an $\alpha$-particle or a $\beta$-particle. How many stages are there in the decay sequence?

Atoms, nuclei and radiation

In an experiment, a steel wire is pulled in order to find the Young modulus for steel. The measurement uncertainties are shown below. measurement / uncertainty: - load on wire: $\pm 2\%$ - length of wire: $\pm 0.2\%$ - diameter of wire: $\pm 1.5\%$ - extension: $\pm 1\%$ What is the percentage uncertainty in the Young modulus?

Stress and strain

Approximately what is the mass of a uranium nucleus?

Atoms, nuclei and radiation

The acceleration of free fall on the Moon is one-sixth of the value on Earth. On Earth, a stone takes time $t$ to fall from rest through a distance of $2\,\text{m}$. How long does a stone take to fall from rest through a distance of $2\,\text{m}$ on the Moon?

Equations of motion

Which graph shows the motion of a car moving along a straight road with a speed that increases uniformly as time passes?

Equations of motion

What does the principle of conservation of momentum state?

Linear momentum and its conservation

Water is driven through a hose-pipe at a rate of $90\,\text{kg per minute}$. It leaves the hose-pipe horizontally at a speed of $20\,\text{m s}^{-1}$. What force must a person holding the hose-pipe apply to stop it from moving backwards?

Momentum and Newton's laws of motion

Two railway trucks, with masses $m$ and $3m$, travel in opposite directions towards one another at speeds $2v$ and $v$ respectively. They collide and remain stuck together. What is the speed of the trucks after the collision?

Linear momentum and its conservation

A $0.10\,\text{kg}$ mass is transported to Mars and then measured using a spring balance and a lever balance. The acceleration due to gravity on Mars is $38\%$ of the value on Earth. What readings would the two balances show on Mars? (Assume that on Earth $g = 10\,\text{m s}^{-2}$.)

Equilibrium of forces

A glider is moving downward at a steady speed, making an angle of $15^{\circ}$ with the horizontal. The diagram indicates the directions of the lift $L$, air resistance $R$ and weight $W$ that act on the glider. Which vector triangle could show the forces acting on the glider?

Equilibrium of forces

A ball is descending at terminal speed in still air. The forces acting on the ball are upthrust, viscous drag and weight. What is the sequence of these three forces in order of increasing magnitude?

Equilibrium of forces

A uniform ladder is leaning on a vertical wall where friction is negligible. The base of the ladder is on rough ground, so friction acts there. The top of the ladder is at height $h$ above the ground, and the foot of the ladder is $2a$ from the wall. The diagram displays the forces acting on the ladder. Which equation is obtained by taking moments?

Turning effects of forces

A mass suspended from the lower end of a spring moves up and down repeatedly. At which positions in the motion of the mass do the gravitational potential energy of the mass (GPE), the elastic potential energy in the spring (EPE) and the kinetic energy of the mass (KE) reach their maximum values?

Energy conservation

A mass $m$ is placed in a uniform gravitational field. As the mass undergoes a displacement $x$ from P to Q, it loses potential energy $E$. Which row correctly gives the magnitude and the direction of the acceleration due to gravity in this field?

Gravitational potential energy and kinetic energy

A small electric motor is fixed on a workbench, as illustrated. The motor is linked to a $6.0\,\text{V}$ supply and the current through the motor is $0.50\,\text{A}$. The motor has an efficiency of $50\%$. What is the time taken to raise a mass of $200\,\text{g}$ through a height of $90\,\text{cm}$?

Potential difference and power

A projectile is projected at $45^{\circ}$ above the horizontal with initial kinetic energy $E$. If air resistance is ignored, what is the kinetic energy of the projectile at its maximum height?

Energy conservation

What is the correct term for a substance made of long-chain molecules that are entangled and curled up?

Elastic and plastic behaviour

Which statement concerning molecules in a gas is correct?

Non-uniform motion

The diagram depicts the atoms in a substance, with the atoms positioned at the corners of a cube. At a given temperature, the mean spacing between the atoms is $15\,\text{nm}$. If the temperature changes so that the mean spacing increases to $17\,\text{nm}$, by what factor does the density of the substance change?

Density and pressure

Which unit is equal to the unit of electric field strength?

Potential difference and power

A stress-strain graph for a glass rod, plotted up to the point where it fractures, is displayed below. Which statement about the glass rod is correct?

Elastic and plastic behaviour

A rubber band is elongated by attaching weights to it, and the results are used to draw a force-extension graph. What is the best estimate of the strain energy stored in the rubber band when its extension is $30\,\text{cm}$?

Elastic and plastic behaviour

Which statement concerning electromagnetic radiation is correct?

Electromagnetic spectrum

As sound moves through air, the air particles oscillate. A graph of displacement against time for one air particle is shown. Which graph most accurately represents how the kinetic energy of the air particle changes with time?

Progressive waves

Which statement gives a situation in which polarisation could not happen?

Polarisation

A stationary sound wave forms inside a tube. Which statement describes the speed of the wave?

Stationary waves

As illustrated, two identical loudspeakers are joined in series to an a.c. supply. Which graph best represents the change in sound intensity with distance along the line $XY$?

Interference

A diffraction grating experiment is arranged with yellow light of wavelength $600\,\text{nm}$. The grating has a slit separation of $2.00\,\mu\text{m}$. Determine the angular separation $(\theta_2 - \theta_1)$ between the first-order and second-order maxima for the yellow light.

The diffraction grating

The diagram depicts two horizontal metal plates arranged parallel to each other. A potential difference $V$ exists across the plates. A tiny charged liquid droplet, positioned halfway between the plates, remains stationary because its weight is balanced by the electric force acting on it. The acceleration of free fall is $g$ and the electric field strength is $E$. What is the sign of the charge on the droplet, and what is the charge-to-mass ratio of the droplet?

Potential difference and power

The diagram depicts two metal plates linked to a constant high voltage. Which graph illustrates how the electric field strength $E$ at the halfway point between the two plates changes as the separation $d$ between the plates is increased?

Potential difference and power

The diagram indicates the reading shown by an analogue ammeter. Which digital ammeter reading matches the analogue ammeter reading?

Practical circuits

$B_1$, $B_2$ and $B_3$ are three identical lamps. They are joined to a battery with zero internal resistance, as shown. At first the switch is closed. The switch is then opened and lamp $B_3$ goes out. What change occurs to the brightness of lamps $B_1$ and $B_2$ when the switch is opened?

Practical circuits

A battery is labelled $9.0\,\text{V}$. What is meant by this?

Potential difference and power

A pencil is used to make a line of length $30\ \text{cm}$ and width $1.2\ \text{mm}$. The resistivity of the material in the pencil is $2.0 \times 10^{-5}\ \Omega\,\text{m}$ and the resistance of the line is $40\ \text{k}\Omega$. What is the thickness of the line?

Resistance and resistivity

Three wires are joined one after another to form a conductor. Although each wire is made from the same metal, their cross-sectional areas are different. A current $I$ flows through the conductor. At point Y on the conductor, the potential is zero. Which graph most accurately shows how potential $V$ changes with distance along the conductor?

Resistance and resistivity

The graph illustrates the way the electric current $I$ in a conducting liquid changes as the potential difference $V$ across it changes. At which point on the graph is the resistance of the liquid lowest?

Resistance and resistivity

For two resistors with resistances $R_1$ and $R_2$ arranged in parallel, the total resistance $R_T$ is given by the formula below. $\frac{1}{R_T} = \frac{1}{R_1} + \frac{1}{R_2}$ Which statement is used in deriving this formula?

Resistance and resistivity

In the potentiometer circuit shown, the ammeter shows a reading of zero. The light-dependent resistor (LDR) is then covered, and the ammeter now shows a non-zero reading. Which change could make the ammeter reading zero again?

Practical circuits

Six resistors, each with resistance $R$, are arranged as shown. The total resistance is $66\,\text{k}\Omega$. What is the value of $R$?

Resistance and resistivity

Which of the following statements about $\alpha$-particles is correct?

Atoms, nuclei and radiation

The isotope $^{222}_{86}\text{Rn}$ undergoes a decay chain, through a series of emissions, to produce the isotope $^{206}_{82}\text{Pb}$. At each step in the decay chain, either an $\alpha$-particle or a $\beta$-particle is emitted. What is the number of stages in the decay chain?

Atoms, nuclei and radiation

A steel wire is pulled taut in an experiment to determine the Young modulus for steel. The measurement uncertainties are listed below: - load on wire: $\pm 2\%$ - length of wire: $\pm 0.2\%$ - diameter of wire: $\pm 1.5\%$ - extension: $\pm 1\%$ What percentage uncertainty is there in the Young modulus?

Stress and strain

Approximately what is the mass of a nucleus of uranium?

Atoms, nuclei and radiation

The acceleration of free fall on the Moon is one-sixth of the value on Earth. On Earth, a stone takes time $t$ to fall from rest through a distance of $2\,\text{m}$. What is the time taken for a stone to fall from rest through a distance of $2\,\text{m}$ on the Moon?

Equations of motion

Which graph shows the motion of a car moving along a straight road at a speed that rises uniformly over time?

Equations of motion

What does the principle of conservation of momentum state?

Linear momentum and its conservation

Water is driven through a hose-pipe at a mass flow rate of $90\,\text{kg per minute}$. The water leaves the hose-pipe horizontally at a speed of $20\,\text{m s}^{-1}$. Which force must be exerted by a person holding the hose-pipe to stop it moving backwards?

Momentum and Newton's laws of motion

Two railway trucks with masses $m$ and $3m$ are travelling in opposite directions towards each other with speeds $2v$ and $v$ respectively. They collide and then remain stuck together. What is the speed of the trucks immediately after the collision?

Linear momentum and its conservation

For a vehicle travelling at speed $v$, the stopping distance $d$ after the brakes are applied is given by $d = kv^2$, where $k$ is a constant. State the unit of $k$ written in SI base units.

SI units

The graph shows a body experiencing a changing resultant force, which makes its momentum change. At which point is the resultant force greatest?

Momentum and Newton's laws of motion

A golf ball with mass $m$ is dropped from a height $h_1$ onto a rigid surface and then rebounds to a height $h_2$. Its momentum immediately before impact is different from its momentum immediately after leaving the surface. What is the overall change in the momentum of the golf ball between these two moments? (Ignore air resistance.)

Momentum and Newton's laws of motion

A sealed cylindrical steel can rests below the surface of water. What is the source of the upthrust acting on the can?

Density and pressure

A cylinder whose weight is $W$ rests on a smooth inclined plane. The force exerted by the plane on the cylinder is $R$. A thread is fastened to the cylinder’s surface, and its free end is secured. Which diagram represents the cylinder in equilibrium?

Equilibrium of forces

A uniform metre rule with mass $100\text{ g}$ is held up by a pivot at the $40\text{ cm}$ mark and by a string at the $100\text{ cm}$ mark. The string runs over a frictionless pulley and supports a mass of $20\text{ g}$, as shown in the diagram. At which mark on the rule should a $50\text{ g}$ mass be hung so that the rule is in balance?

Turning effects of forces

A constant force $F$, applied to a car of mass $m$, lifts the car along a slope for a distance $s$ with constant speed $v$. The angle between the slope and the horizontal is $\alpha$. Which expression represents the efficiency of the process?

Gravitational potential energy and kinetic energy

The diagram represents a particle X, with kinetic energy $E_k$, moving towards a collision with a stationary particle Y. The two particles are of equal mass. Following the collision, X and Y continue together as one larger particle. How much kinetic energy is lost in the collision?

Linear momentum and its conservation

A box of weight $30\,\text{N}$ is released from rest on a ramp inclined at an angle of $30^\circ$ to the horizontal. As the box moves down the ramp, it descends a vertical distance of $8.0\,\text{m}$. While it is moving, a constant frictional force of $10\,\text{N}$ acts on the box. What is the kinetic energy of the box after it has fallen through this distance?

Gravitational potential energy and kinetic energy

A positive charge is subjected to a force $F$ when it is at point X in a uniform electric field. The charge is then transferred from point X to point Y. The diagram shows distances $r$ and $s$. What is the change in the potential energy of the charge?

Potential difference and power

A van driver alters the braking force on a van so that it moves at a constant speed downhill from P to Q. The magnitude of the change in the van’s kinetic energy is $\Delta E_k$. The magnitude of the change in its gravitational potential energy is $\Delta E_p$. Which statement is correct?

Gravitational potential energy and kinetic energy

Which list includes one vector quantity and two scalar quantities?

Scalars and vectors

At sea level, atmospheric pressure is $100\,\text{kPa}$. Sea water has a density of $1020\,\text{kg m}^{-3}$. At what depth in the sea is the total pressure $110\,\text{kPa}$?

Density and pressure

A student is investigating Brownian motion. With a microscope, she sees smoke particles inside a glass container, lit by a strong light. The smoke particles follow a zig-zag path, with their speed and direction continually changing. What will happen to the smoke particles if the air in the container is heated?

Non-uniform motion

The diagram represents two immiscible liquids, P and Q. They are balanced in an open U-tube at equilibrium. What is the ratio $\frac{\text{density of P}}{\text{density of Q}}$?

Density and pressure

What does the term ultimate tensile stress of a material mean?

Stress and strain

The graph presents how a metal sample responds when it is stretched until plastic deformation begins. What is the total work done in stretching the sample from zero to $12.0\,\text{mm}$ extension? Approximate the calculation by treating the curve $XY$ as a straight line.

Elastic and plastic behaviour

Two springs, one having spring constant $k_1 = 4\,\text{kN m}^{-1}$ and the other having spring constant $k_2 = 2\,\text{kN m}^{-1}$, are arranged as shown. What is the combined extension of the springs when they are supporting a load of $80\,\text{N}$?

Elastic and plastic behaviour

Which of the following statements concerning waves is correct?

Progressive waves

The graph below shows how the intensity $I$ of a stationary sound wave in air changes with distance $x$. The speed of sound in air is $340\,\text{m s}^{-1}$. Find the frequency of the sound wave.

Stationary waves

Plane wavefronts in a ripple tank move through a gap, as illustrated. Which property of the wave is different at $Q$ from at $P$?

Diffraction

An organ pipe with length $l$ is open at both ends. When stationary waves are established in the pipe, notes are heard. The speed of sound in the air column is $v$. What is the lowest (fundamental) frequency of the note produced by the pipe?

Stationary waves

For the circuit illustrated, an analogue ammeter is going to be recalibrated so that it acts as a thermometer. The graph indicates how the thermistor resistance $R$ varies with temperature $T$. Which diagram might show the temperature scale on the ammeter?

Practical circuits

Interference fringes appear on a screen due to double-slit interference with light of wavelength $600\,\text{nm}$. The fringe spacing is $4.0\,\text{mm}$ and the slit separation is $0.60\,\text{mm}$. Determine the distance between the double slit and the screen?

Interference

Unevenly charged regions form inside a cloud, as shown. For region $X$, which diagram shows the direction of the electric field and the initial direction in which electrons would move?

Electric current

The trajectory of an electron, initially moving at speed $v$, in the uniform electric field between two parallel plates is illustrated. The vertical deflection $x$ is recorded at the right-hand edge of the plates. The separation between the plates is reduced to half its original value. The potential difference across the plates stays unchanged. What will the electron’s new deflection be if it starts with the same initial speed $v$?

Equations of motion

A metal wire with length $0.50\,\text{m}$ has resistance $12\,\Omega$. What resistance will a wire of length $2.0\,\text{m}$ have if it is made from the same material but has half the diameter?

Resistance and resistivity

A student was given two resistors with no labels. To find the resistance of the resistors, the circuit shown below was assembled. The resistors were placed one at a time between P and Q, and the current readings were recorded. The voltage readings were recorded with no resistors connected and then again with each resistor separately. The results were typed into a spreadsheet, as shown. The student did not fill in the column headings. Which arrangement of the headings would be correct?

Practical circuits

A potential divider is made from resistors with resistance $R_1$ and $R_2$ joined in series across a source of potential difference $V_0$. The potential difference across $R_1$ is $V_{\text{out}}$. Which alterations to $R_1$ and $R_2$ would increase the value of $V_{\text{out}}$?

Potential dividers

An extension lead is being used to connect a $240\,\text{V}$ electrical supply to a heater, as illustrated. A voltmeter shows the potential difference (p.d.) across the heater is $216\,\text{V}$, and an ammeter shows that the current through the heater is $7.7\,\text{A}$. What is the total resistance of the extension lead?

Practical circuits

For the circuit diagram shown, assume that the ammeters have negligible resistance and the voltmeters have infinite resistance. The meter readings are $I_1$, $I_2$, $V_1$ and $V_2$, as indicated on the diagram. Which statement is correct?

Practical circuits

A radioactive isotope of an element has a nucleus that releases an alpha particle. After that, the daughter nucleus releases a beta particle, and then the daughter nucleus from that reaction releases a second beta particle. Which statement describes the final nuclide formed?

Atoms, nuclei and radiation

A nuclear reaction is displayed. $^{{238}}_{{92}}\text{U} + ^{{4}}_{{2}}\text{He} \rightarrow ^{{241}}_{{94}}\text{Pu} + X$. What is the product $X$?

Atoms, nuclei and radiation

The diagram shows a section of a thermometer. What is the correct thermometer reading, and what is the uncertainty in this reading?

Errors and uncertainties

Alpha, beta and gamma radiations: 1 are absorbed to different extents in solids, 2 respond differently in an electric field, 3 respond differently in a magnetic field. These diagrams show these behaviours. Which three labels on the diagrams represent the same type of radiation?

Atoms, nuclei and radiation

The resistance $R$ of a resistor is to be found. The current $I$ through the resistor and the potential difference $V$ across it are recorded. The readings, together with their uncertainties, are $I = (2.0 \pm 0.2)\,\text{A}$ and $V = (15.0 \pm 0.5)\,\text{V}$. The value of $R$ is worked out as $7.5\,\Omega$. What is the uncertainty in this value for $R$?

Errors and uncertainties

In an experiment designed to find the acceleration of free fall $g$, a ball-bearing is supported by an electromagnet. Once the current to the electromagnet is turned off, a clock begins and the ball-bearing drops. After travelling a distance $h$, the ball-bearing hits a switch that stops the clock, which records the time $t$ for the fall. Which expression can be used to calculate the value of $g$?

Equations of motion

The diagram displays a velocity-time graph for a mass moving up and down at the end of a spring. Which point shows the velocity of the mass when it is at the lowest point in its motion?

Non-uniform motion

A ball is let go from rest on a smooth slope XY. It travels down the slope, continues across a smooth horizontal surface YZ and then rebounds inelastically at Z. It then returns to Y and finally comes to rest momentarily at some point on XY. Which velocity-time graph shows the motion of the ball?

Equations of motion

A man’s weight on Mars is $240\text{ N}$, and the acceleration of free fall there, $g$, is $4\text{ m s}^{-2}$. On the Moon, $g$ is $2\text{ m s}^{-2}$. Which of the following statements is correct?

Momentum and Newton's laws of motion