A 500kg car which was initially at rest travelled with an acceleration of 5m sec-2, its kinetic energy after 4 seconds was
-
A.
105J -
B.
2.5 x 103J -
C.
2 x 103J -
D.
5 x 103J -
E.
5 x 105J`
Correct Answer: Option A
Explanation
K.E = (frac{1}{2})mv2; m (at + u)2
since, v = at + u = (frac{1}{2}) x 500 [(5 x 4)+ 0]2
= 105J