A motorboat starts from rest on still water and moves in a straight line according to…
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A motorboat starts from rest on still water and moves in a straight line according to the plan below:
• accelerates uniformly for 8 s with a constant acceleration of 1.5 m/s²,
• then travels at the speed reached for the next 20 s,
• finally the engine is switched off and the boat slows down uniformly to 2 m/s in the following 10 s.
Answer the following:
(i) Construct the velocity–time graph for the entire motion described.
(ii) Determine the maximum speed attained by the boat.
(iii) Using the graph, calculate the total distance travelled during the 38 s of motion.
(iv) Find the average speed of the boat for the whole journey.