Question

a body of mass 10kg moving with 20ms-¹ acted upon by a force. the velocity of the body changes to 40ms-¹ during 1sec. find the magnitude of the force?

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Answer 1

Answer:

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

=2:1