A motorboat moves through still water while its engine delivers a constant mechanical…
PHYSICS · Multi-part · GCSE · Physics · Energy · Energy
Problem
A motorboat moves through still water while its engine delivers a constant mechanical power of 5.0kW. At a certain speed, the total resistive force of the water on the hull is measured to be 800N. Assume that the resistive force remains constant over the small speed range considered.
(a) Calculate the speed of the boat under these conditions.
(b) If additional cargo increases the water resistance to 1000N while the engine power remains the same, find the new speed.
(c) Compare the two speeds and explain, with calculations, how the change illustrates the relationship between force and velocity for a fixed power output.