Question

. A body of mass 50 kg changes its velocity from 10 m/s to 60 m/s when acted by a force for time 10 s. If the same force is applied on a body of mass 10 kg moving with velocity of 5 m/s ,for time 10 s ,Calculate the final velocity of the object .

Answer 1

Explanation:

Given , Mass of object ,m=10 kg

Velocity of object , v=20ms

−1

Initial Kinetic energy , K

1

=

2

1

×10×20

2

=2000 J

Now Final mass ,m

2

=20 kg

Final Velocity , v

2

=10m/s

Final Kinetic energy , K

2

=

2

1

×20×10

2

=1000 J

Required Ratio=

K

2

K

1

=

1000

2000

=2