WAEC - Physics (1992 - No. 11)
A body of mass 5kg falls from a height of 10m above the ground. What is the kinetic energy of the body just before it strikes the ground? (Neglect energy losses and take gravity as 10ms^2)
5J
25J
250J
500J
625J
解释
v2 = u2 + 2gh = 0 + 2 x 10 x 10
v2 = 200; K.E = 1/2mv2 = 1/2 x 5 x 200 = 500J
v2 = 200; K.E = 1/2mv2 = 1/2 x 5 x 200 = 500J