What is the kinetic energy of an object with a mass of # 16 kg# that has been in freefall for # 4 s#?

1 Answer
Mar 2, 2016

Answer:

The kinetic ebergy will be #E_k=1/2mv^2# with #m=16kg#

Explanation:

Now the speed #v#:
Acceleration of gravity #g=9.81m//s^2#
Which means that after #t=4s# the velocity will be:
#v=gxxt=9.81xx4=39.24m//s#

Using this in the original formula we get:

#E_k=1/2xx16xx(39.24)^2=12318J~~12.3kJ#