Question

A man uses a lever jack to lift a 2.00 x 10^3 kg car to change a tire. Each stroke of the jack lifts the car a distance of 5.00 x 10^-3 m. The vertical displacement of the handle is 0.75 m for each stroke. How much total force does he use with each stroke of the jack?

A) 19,600 N
B) 3.0 x 10^5 N
C) 131 N
D) 2.9 x 10^6 N

Answer 1

Convert weight to Newtons:

2 * 10^3 * 9.81 = 19.62*10^3 N

Find the mechanical advantage of the handle :

.75/.005 = 150

Now divide the weight in Newtons, by the mechanical advantage:

(19.62/150)* 10^3 = 130.8 N

Round to 131 N

The answer is C.