1. A 2000kg truck at rest accelerates to 45m/s in 7 seconds. What is its change in kinetic energy?

2025000 J

Explanation:

The formula for kinetic energy is KE=.5 (m) (v²).

The initial kinetic energy is 0 because it is at rest ...5 (m) (0) = 0.

To calculate the final kinetic energy, use the kinetic energy equation. KE =.5 (2000) (45²) = 2025000 J.

To find the change in kinetic energy, you do KE (f) - KE (i). 2025000-0 = 2025000 J.