A compact sports car is advertised as having an engine rated at
PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Work Energy and Power · Work Energy and Power
Problem
A compact sports car is advertised as having an engine rated at 250hp. When test-driven on a straight level track, the 1200kg car accelerates from rest to a cruising speed of 25ms−1.
(a) Convert the engine’s power rating to kilowatts.
(b) Assuming the engine can deliver its full rated power throughout the acceleration and that all of that power goes into increasing the car’s kinetic energy, calculate the minimum time required for the car to reach 25ms−1. Neglect air resistance and internal losses.
(c) Discuss one physical reason why the actual time measured on the track may be longer than the value calculated in part (b).