Tori experiments with pulleys in physics class. She applies 70 newtons of force to a single pulley to lift a bowling ball. By ad
ding another pulley, she’d get a mechanical advantage of 2. What’s the minimum input force she’ll need to lift the ball if she adds another pulley? A.
2 N
B.
35 N
C.
68 N
D.
70 N
E.
140 N
