Calculating the energy of moving objects (Ek=1/2mv2)

12 questions

1. Which properties of an object can be increased so it has more energy in its kinetic store?
2. Why does a shopping trolley that has been pushed and then let go of come to a stop?
3. What happens to the amount of work done moving a car, if the car is pushed with the same size force for three times the distance?
4. In which of these situations does the applied force **not** do any work?
5. How would you calculate the work done by a catapult in shooting a small ball forward?
6. A catapult does work on a small ball to fire it vertically up into the air. What is the amount of work done on the ball equal to?
7. How much energy will be transferred to the kinetic store if three times the amount of work is done on kicking a football?
8. If friction and air resistance are ignored, how much energy is dissipated by a toy car moving across a table?
9. What happens to the amount of energy in the kinetic store of a ball if it is moving at two times the speed?
10. What is kinetic energy?
11. What is the kinetic energy of a discus of mass 2 kg moving at a speed of 8 m/s?
12. What is the mass of a javelin that has a kinetic energy of 72 J and a speed of 12 m/s?

License: OGL