A 5.00-kg cat that is initially at rest jumps down from the top of a bookcase that is 3.00 m tall. What is the cat's speed when it reaches the floor?
The cat's potential energy before jumping is:
\(PE=mgh\)
\(PE=5\times9.81\times3\)
\(PE=147J\)
This will all be transferred to kinetic energy just before the cat hits the floor.
\(KE=\frac{mv^2}{2}\)
\(147=\frac{5v^2}{2}\)
\(v=7.67m/s\)
