Bennett Mechanical Test Pulleys and Levers 5

Question 1

A nutcracker that pivots at the hinged end is which class of lever?

Accepted Answer

Second-class lever

Answer

A nutcracker is a second-class lever with the load (nut) between the fulcrum and the effort.

Question 2

A block and tackle with 5 supporting rope segments lifts a 500 lb load. What effort is needed (ignoring friction)?

Accepted Answer

100 lb

Answer

With a mechanical advantage of 5, effort equals 500 ÷ 5 = 100 lb.

Question 3

What happens to the force needed as you move the fulcrum closer to the load on a lever?

Accepted Answer

Less force is needed

Answer

Moving the fulcrum closer to the load lengthens the effort arm, reducing the force required.

Question 4

A wheelbarrow lets a worker lift a heavy load with less effort because it is a:

Accepted Answer

Second-class lever

Answer

A wheelbarrow is a second-class lever with the wheel as the fulcrum and the load between it and the handles.

Question 5

If a movable pulley gives a mechanical advantage of 2, how far must you pull the rope to raise the load 3 ft?

Accepted Answer

6 ft

Answer

With a mechanical advantage of 2, you pull twice the load distance, so 3 × 2 = 6 ft.

Bennett Mechanical Test Practice Test