Question

A body of mass 1 kg has kinetic energy 1J when its speed is 

(1) 0.45 m/s 

(2) 1 m/s 

(3) 1.4 m/s 

(4) 4.4 m/s

Answer 1

Correct option is (3) 1.4 m/s 

K.E = 1/2 m v² 

1 = 1/2 x 1 x v² 

2 = v² 

v² = 2 

v = √2 or 1.4m/s