Question

Calculate the change in kinetic energy of a moving body if its velocity is reduced to one third of the initial velocity.​

Answer 1

Answer:

Given: Initial velocity =v; Final velocity =

3

v

Initial kinetic energy k

1

=

2

1

×m×v

2

Final kinetic energy k

2

=

2

1

×m×(

3

v

)

2

=

9

1

×

2

1

mv

2

Change in kinetic energy =

2

1

mv

2

−

9

1

×

2

1

mv

2

=

2

1

mv

2

(1−

9

1

)

=

9

8

×

2

1

×mv

2

=

9

8

× Initial kinetic energy