Okay, first off, the formula for Kinetic Energy is:
<em>KE = 1/2(m)(v)^2</em>
<em>m = mass</em>
<em>v = velcoity (m/s)</em>
Using this formula, we can then calculate the kinetic energy in each scenario:
1) KE = 1/2(100)(5)^2 = 1,250 J
2) KE = 1/2(1000)(5)^2 = 12,500 J
3) KE = 1/2(10)(5)^2 = 125 J
4) KE = 1/2(100)(5)^2 = 1,250 J