Physics 5054 · O Level · Balanced and unbalanced forces

Balanced and unbalanced forces — practice question

Fig. 1.1 illustrates the directions of four forces acting on a racing car while it moves along a horizontal straight line. In Fig. 1.1, the arrows are labelled force A (upwards), force B(to the right), force C (downwards) and force D (to the left).
(a)[1]

Join each box on the left to the description that correctly names its force.

(b(i))[1]

The table gives the magnitudes of the forces acting on the car at one instant. The gravitational field strength $g$ is $10\,\text{N kg}^{-1}$. Calculate the mass of the car.

(b(ii))[1]

Calculate the resultant force on the car.

(b(iii))[2]

Calculate the acceleration of the car.

(c)[2]

At a different time, the car is moving at speed $u$. It then accelerates for $5.0\,\text{s}$ at $1.6\,\text{m s}^{-2}$, and its speed becomes $20\,\text{m s}^{-1}$. Calculate the value of $u$.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: A - contact force or reaction force

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI