A long tube is filled with oil. A small ball is kept stationary at the oil surface. At time $t = 0$, the ball is let go and starts to move vertically downward through the oil.
Fig. 1.1 depicts the ball as it falls through the oil.
When the ball starts moving through the oil, it accelerates.
(a)[1]
Define the term acceleration.
(b)[2]
Calculate the resultant force on the ball when it is accelerating downwards at $2.8\text{ m s}^{-2}$.
(c(i))[4]
Describe what occurs to the acceleration from $t = 0$ to $t = 0.040\text{ s}$. Explain why this occurs.
(c(ii))[3]
By drawing a tangent on Fig. 1.2, determine a value for the ball’s acceleration at $t = 0.010\text{ s}$.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Acceleration is the change in velocity per unit time OR the rate at which velocity changes OR a = Δv / Δt” …