Question

What is the velocity of a body of mass 100 g having K.E. of 20 J ?
(1) 2 m/s
(2) 20 m/s
(3) 40 m/s
(4) None of these

Answer 1

I think None of them.

Answer 2

20m/s

1/2mv^2=20

1/2(100* 10^-3)V^2=20 (100* 10^-3=0.1)

V^2=20*2/0.1

V^2=40/0.1=400

V=20