A toy car starts from rest at the origin of a straight horizontal track. Its displacement x from the origin is recorded at equal time intervals as shown in the table below.
Time t (s): 0, 1, 2, 3, 4, 5
Displacement x (m): 0.0, 0.8, 3.2, 7.2, 12.8, 20.0
Answer the following questions related to the motion of the car.
(a) Plot the given data on a suitable scale to obtain the displacement–time graph for the car.
(b) Draw a tangent to the curve at t=3s on your graph. Using the tangent, estimate the instantaneous velocity of the car at this instant.
(c) By inspecting the slopes of the graph, state whether the car is moving faster at t=2s or at t=4s. Justify your answer with reference to the steepness of the graph.
(d) Explain qualitatively how the nature of the curve indicates whether the car is undergoing uniform or non-uniform motion in the time interval shown.