What is the kinetic energy of an object with a mass of #5 kg# that has been in freefall for #8 s#?

1 Answer
Feb 5, 2016

Answer:

#15.366kJ#

Explanation:

Assuming the object has fallen from rest near earth, we may use the equations of motion for constant acceleration to find its velocity after 8 seconds :

#v=u+at#

#=0+(9,8)(8)#

#=78,4m//s#

Hence its kinetic energy at this stage is

#E_k=1/2mv^2#

#=1/2xx5xx78.4^2#

#=15,366kJ#