WAEC - Physics (2011 - No. 9)
A stone of mass 300g is released from rest from the top of a bulding of height 100m. Determine the kinetic energy gained by the stone when it is a quarter way down from the point of release.[g = 10 ms-2]
750.0J
225.0J
75.0J
22.5J
Vysvetlenie
K.E = P.E = mgh
= 0.3 x 10 x 100 - 0.3 x 10 x 75
= 75J
= 0.3 x 10 x 100 - 0.3 x 10 x 75
= 75J