JAMB - Physics (1987 - No. 6)
A body rolls down a slope from a height of 100m. its velocity at the foot of the slope is 20ms-1. What percentage of its initial potential energy is converted into kinetic energy? [g = 10ms-1]
40%
35%
20%
15%
คำอธิบาย
P.E = mgh = 1000m joules
K.E = \(\frac{1}{2}\)mv2 = 200m joules
%converted = \(\frac{200m}{1000m}\) x 100
= 20%
K.E = \(\frac{1}{2}\)mv2 = 200m joules
%converted = \(\frac{200m}{1000m}\) x 100
= 20%