Calculating energy changes - with complex examples (KE and dGPE)

12 questions

1. Match each symbol in the equations \Delta GPE = mg \Delta h and KE = ½mv^2 with the quantity it represents.
2. Match the following quantities to their units.
3. Which of the following statements are correct?
4. An eagle with a mass 4.0 kg flies at a speed 15 m/s. Which of the following is the amount of energy in its kinetic store?
5. A book of mass 1.6 kg falls off a shelf onto the floor. The shelf is 2.0 m above the floor. Which of the following is the change in energy in the gravitational store? Use g = 10 N/kg.
6. An apple of mass 200 g falls from a branch that is 150 cm above the ground. Which of the following is the change in energy in the gravitational store? Use g = 10 N/kg.
7. The principle of ___ states that total amount of energy at the end of a process is always the same as the total amount of energy at the beginning.
8. A plate is dropped. If no energy is dissipated during the fall, the final speed of the plate before it hits the ground is 4 m/s.If energy is dissipated, which of the following statements is correct?
9. A 0.20 kg ball is thrown vertically upwards and reaches a maximum height of 2.1 m. Assuming that no energy is dissipated, the ball’s kinetic energy at the start is ___ J.Use g = 10 N/kg.
10. A child sledges down a hill of height 12 m. The total mass of child and sledge is 30 kg. Assuming no energy is dissipated, the kinetic energy at the bottom of the hill is ___ J.Use g = 10 N/kg.
11. A mountain goat with a mass of 52 kg jumps vertically upwards, leaving the ground at speed 6.0 m/s. The maximum height that the goat can reach is ___ m.Use g = 10 N/kg.
12. A frog with a mass of 0.025 kg jumps vertically upwards and reaches a height of 0.40 m. Which of the following is the frog’s speed at the moment it jumps? Use g = 10 N/kg.

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