(a) Two bodies A and B of masses 10 kg and 20 kg respectively are at the same height above the ground. Which of the two has greater potential energy?
(b)
(i) Two toy-cars A and B of masses 500 g and 200 g respectively are moving with the same speed. Which of the two has greater kinetic energy?
(ii) A cyclist doubles his speed. How will his kinetic energy change: increases, decreases or remains the same?
When a boy doubles his speed, his kinetic energy becomes ___times the initial kinetic energy.