28. Work-Energy Theorem

28. Work-Energy

Multiple Choice

A 2400 kg car accelerates from a speed of 3 m/s to 10 m/s. How much does the kinetic energy change?

• 109,200 J

• 8,400 J

• 12,000 J

• 3,600 J

Multiple Choice

The engine of a 1300 kg is doing 50,000 J of work on it. If it starts from rest, how fast does it end up going?

• 76.9 m/s

• 8.8 m/s

• 17.5 m/s

• 153.8 m/s

Multiple Choice

Can work be negative?

• No

• Yes

Multiple Choice

When a 2000 kg car brakes, negative work is done on it (because it slows down). It comes to a full stop at a red light. This requires – 400000 J of work. How fast was it initially going?

• 400 m/s

• 20 m/s

• 800 m/s

• 40 m/s