# A ball has a kinetic energy of 100 J. What would be the kinetic energy of a ball with twice the mass and half the momentum?

##### 1 Answer

#### Explanation:

There exist a relationship between

Proof for this formula

#"L.H.S."="KE"#

#color(white)("L.H.S.")=1/2m*v^2#

#color(white)("L.H.S.")=1/2*(m*v)^2*1/m#

#color(white)("L.H.S.")=1/(2m)*p^2#

#color(white)("L.H.S.")="R.H.S."#

The question states that

#p_2=1/2p_1# and#m_2=2m_1#

where

The kinetic energy of the second ball would be