Part 1
A 1260 kg car accelerates uniformly from rest
to 4.65 m/s in 2.6 s.
Find the work done on the car in this time.Answer in units of J.
Part 2
Find the average power delivered by the en-
gine in the first 1.768 s.
Answer in units of W.
Part 3
Find the instantaneous power delivered by the
engine at t2 = 1.274 s.
Answer in units of W.
1. Regardless of the time required, the work done equals thwe kinetic energy change.
2. Assuming that the acceleration rate and force are constant, after 1.768 s, the fraction of the final KE will be
(1.768/2.6)^2 = (0.68)^2 = 0.4624
Compute that amount of energy and divide it by 1.728 s for the average power.
3. Instantaneous power = F*V
Use the time to get the instantaneous V. Get F from F = Ma