Problem

You are playing tetherball because you are seven years old and you have nothing better to do.  If the tetherball has a mass of 1 kg and the rope is 1.5 m long and can withstand a maximum force of 240 N, what is the maximum speed that the tetherball can have before the rope breaks?

Problem

You ride a roller coaster with a loop-the-loop after eating a chili cheese dog and a large order of chili cheese fries and drinking a frozen lemonade.  Your mass after this salubrious lunch is 77 kg.  Your speed at the bottom of the loop is 31 m/s, and your speed at the top of the loop is 13.0 m/s.  What is the normal force that the coaster car exerts on your butt at the top of the loop?  At the bottom of the loop?