Chapter 11: Work and Energy

• W = Fs
• KE = ⅔mv²
• PE = mgh
• Power = W/t

Q1. Find the kinetic energy of a 2 kg object moving at 3 m/s.

Solution

KE = ⅔mv² = ⅔ × 2 × 9 = 9 J

Q2. What is the work done in lifting a 5 kg book to a height of 2 m?

Solution

W = mgh = 5 × 10 × 2 = 100 J