Question

Question #e1ca3

Answer 1

You got it correct.

Explanation:

Let the speed of 2kg ball be `=v` `ms^-1`
1kg ball has speed `=2v` `ms^-1`
Kinetic energy is given as `=1/2mv^2` ......(1)

Using equation (1) we get
`KE_"2kg"=1/2 (2)v^2=v^2` .....(2)
and `KE_"1kg"=1/2(1)(2v)^2=2v^2` ......(3)

Dividing (2) with (3)
`(KE_"2kg")/(KE_"1kg")=v^2/(2v^2)`
`=>(KE_"2kg")/(KE_"1kg")=1/(2)`

`=>` Compared to the 1kg ball, the 2kg ball has half the kinetic energy.