Question

A quarterback throws releases a 400. g football 1.2 meters off of the ground with a speed of 25 m/s. Determine the total energy of the football.
A. 130 J
B. 9.7 J
C. 1300 J
D. 97 J

Answer 1

Kinetic energy is an expression of the fact that a moving object can do work on anything it hits; it quantifies the amount of work the object could do as a result of its motion. And potential energy is the energy that is stored in an object due to its position relative to some zero position.  We calculate as follows:

KE + PE = mv^2 / 2 + mgh 
Total energy = .4(25)^2/2 + .4(9.81)(1.2)
Total energy = 129.71 J = 130 J <------- OPTION A