A skateboarder moves along a straight track following the sequence described below: •…
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A skateboarder moves along a straight track following the sequence described below:
• starts from rest and speeds up uniformly to reach a velocity of 8 m/s in 4 s,
• continues at this velocity without change for the next 3 s,
• finally slows down uniformly to rest in the subsequent 2 s.
Answer the following:
(i) Draw a neatly labelled velocity–time graph for the entire 9 s of motion.
(ii) State the numerical value of the acceleration in each of the three phases and indicate on the graph where each value applies.
(iii) Shade the region on the graph that represents the total displacement and explain why the shaded area has that physical meaning.