Question

Physics Post Lab: Simple Machines

1) Which class of lever does the following belong to?

a. Pliers

      b. Bottle opener

      c. Scissors

      d. Fishing Rod

      e. Wheel Barrow

      f. Nail clipper

    g. Stapler

2) Does the single pulley magnify force, multiply speed, or simply change the direction of the applied force?

3) Archimedes said, “Give me a place to stand, and I will move the world”. Discuss what you think he meant by that!

4) Name three examples not already mentioned of wheel and axle systems.

Answer 1

Part 1

A lever is a simple machine that makes work easier for use; it involves moving a load around a pivot using a force.

There are mainly three class of levers.

1. Type 1
2. Type 2
3. Type 3

In a Type 1 Lever, the pivot (fulcrum) is between the effort and the load. In an off-center type one lever (like a pliers), the load is larger than the effort, but is moved through a smaller distance.

In a Type 2 Lever, the load is between the pivot (fulcrum) and the effort.

In a Type 3 Lever, the effort is between the pivot (fulcrum) and the load.

now coming to your answers

(a). Pliers are Type 1 lever

(b) Bottle opener Type 2 lever

(c) Scissors are Type 1 lever

(d) Fishing Road Type 3

(e) Wheel Barrow Type 2

(f) Nail clipper Type 2

(g) Stapler Type 2

Part 2

We can connect pulleys to each other with a belt and have one pulley drive the other. In this manner we can magnify the force, increase the number of turns or change the direction of the force applied.

So the answer is yes they do.

Part 3

That is to do with the action of levers. The force exerted by a lever is proportional to the ratio of the lengths either side of the pivot. So, to exert an indefinately large force one needs an indefinately long lever - and a place to stand to push on the end of it.

part 4

Three examples of wheel and axle system are:-

1. Doorknob
2. Screwdriver
3. Gears