1. Mary has a mass of 40 kg and sprints at 1 m/s. How much kinetic energy does she have?

2. Roberto has twice the mass his sister Mary has (see above) but runs at the same velocity as Mary. Will his kinetic energy be twice as much? Show your work.

What happens to Roberto’s kinetic energy when he runs twice as fast?

3. Use the kinetic energy formula KE = 0.5 mv2 to complete the practice problems below. Remember, 1 J = 1 kg ∙ m2 /s2 . Also, velocity is v 2 = KE / (0.5 x m), and mass is m = KE / (0.5 v2 ).

4. What is the kinetic energy of a 150 kg object that is moving at a speed of 15 m/s?

5. An object has a kinetic energy of 500 J and a mass of 30 kg. How fast is the object moving?

6. An object moving with a speed of 5 m/s has a kinetic energy of 100 J. What is the mass of the object?

7. What is the kinetic energy of a 1,200 kg object that is moving at a speed of 24 m/s?

Please help ASAP :(