1. Sir Isaac Newton twirls his corded headphones horizontally above his head just for fun. The headphones have a mass of 15kg and are held by its cord which is 25cm long.

a. If the force of tension on the cord is 5.922N, how long does it take to make one complete revolution? (10 points)

b. If the cord lengthens to 0.5 mcmand Sir Isaac Newton keeps the headphones rotating at the same speed as before, how much tension will there be in the cord? (10 points)