# What happens to the kinetic energy of an object if we halve the velocity?

##### 1 Answer

Dec 16, 2017

#### Answer:

See below.

#### Explanation:

Kinetic energy is given by

where

If we halve the object's velocity, we're saying that the final velocity is

So, initially we would have

#K_f=1/2mv_f^2#

#=1/2m*(1/2v_i)^2#

Note that the entire quantity—including both the

#=>1/2m*1/4v_i^2#

Rearranging:

#=>1/4(1/2mv_i^2)#

#=1/4K_i#