What is the kinetic energy of an object with a mass of #3 kg# that has been in freefall for #28 s#?

1 Answer
Dec 21, 2015

Answer:

#112.9"kJ"#

Explanation:

We need to get the velocity of the object after it has fallen under gravity for 28s.

We can use #v=u+at#

This becomes:

#v=0+9.8xx28#

#:.v=274.4"m/s"#

The kinetic energy is given by:

KE = #1/2mv^2#

#:."KE"=1/2xx3xx274.4^(2)=112,943"J"#

#=112.9"kJ"#