Tori experiments with pulleys in physics class. she applies 70 newtons of force to a single pulley to lift a bowling ball. by adding 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?

The minimum input force she'll need to lift the ball is 35 N.

Explanation:

Mechanical advantage of a single pulley is 1. As, she applies 70 N of force to lift the bowling ball, so the output force(weight of the ball) is also 70 N.

Now, adding another pulley gives a mechanical advantage of 2. We have,

M.A = (Output Force)/(Input Force)

Substituting the values we get,

= 35 N

Input force equals to 35 N needs to be applied.

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000