THE WORK–ENERGY THEOREM
Kinetic energy is expressed in joules just like work, since W = K, as in the case we
just saw. In fact, the total work done on an object—or the work done by the net
force—is equal to the object’s change in kinetic energy; this is known as the work–
energy theorem.
Wtotal = ∆KKinetic energy, like work, is a scalar quantity.
- What is the kinetic energy of a baseball (mass = 0.15 kg) moving
with a speed of 20 m/s?
Here’s How to Crack It
From the definition,
- How much work would it take to stop an object that has 30 J of