The velocity–time history of a toy car moving in a straight line is described below:…
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
The velocity–time history of a toy car moving in a straight line is described below:
• From t=0 to t=5s its velocity increases uniformly from 0 to 10m/s.
• From t=5s to t=10s its velocity remains constant at 10m/s.
• From t=10s to t=14s its velocity decreases uniformly to 0m/s.
Answer the following questions related to this motion:
(i) Sketch a velocity–time graph for the entire 14s interval and label each segment clearly.
(ii) Explain the nature of acceleration (positive, zero or negative) in each of the three time intervals.
(iii) State whether the magnitude of retardation in the last interval is greater than, equal to, or less than the magnitude of acceleration in the first interval. Justify your answer from the shape of the graph without performing numerical calculations.
(iv) Describe in words how the velocity of the car changes over the whole journey.