What is the kinetic energy of an object with a mass of #3# # kg# that has been in freefall for #9# # s#?

1 Answer
Feb 26, 2016

Answer:

First step is to calculate the velocity, #v=u+at=0+9.8*9=88.2# #ms^-1#.

Second step is to use this to calculate the kinetic energy, #E_k=1/2mv^2=1/2*3*88.2^2=11669# #J=11.7# #kJ#.

Explanation:

The initial velocity, #u# can be assumed to be #0# #ms^-1# if we are not told otherwise, and the acceleration is just the acceleration due to gravity, #9.8# #ms^-2#.

The kinetic energy is a function of the mass and velocity of the object.