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

First-class lever

Answer

Third-class lever

Answer

Block and tackle

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

250 lb

Answer

500 lb

Answer

2500 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

More force is needed

Answer

Force stays the same

Answer

The lever breaks

Question 4

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

Accepted Answer

Second-class lever

Answer

First-class lever

Answer

Third-class lever

Answer

Fixed pulley

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

3 ft

Answer

1.5 ft

Answer

9 ft

Question 6

Which simple machine is a pulley actually a variation of?

Accepted Answer

A lever (wheel rotating about an axle)

Answer

An inclined plane

Answer

A wedge

Answer

A screw

Question 7

A lever requires 40 lb of effort to lift an 80 lb load. If friction is added, the real effort needed will be:

Accepted Answer

More than 40 lb

Answer

Exactly 40 lb

Answer

Less than 40 lb

Answer

Zero