Knowledge

A force is a push or a pull on an object.

There are three types of forces that act on all objects on earth.
They are friction, gravity and magnetism.

Materials

• string
• ruler
• rubber bands
• sticky tape

Procedure

1. Attach a rubber band to the pencil case with a piece of string.

2. Place the ruler on your desk and rest the pencil case along the ruler.

3. Drag the pencil case along the ruler with the rubber band and try to measure the length of the rubber band. (You need to drag it with a steady, constant force to keep the length of the rubber band constant)

4. Elevate the ruler with a few books so it makes a ramp.
(Another name for a ramp is an inclined plane)

5. Try to drag the pencil case up the ruler with the same force as before. Measure the length of the rubber band as you drag it up.

6. Lift the pencil case up vertically with the rubber band and measure its length.

Oservations

Which is the easiest way to move the pencil case ?

Which method streched the rubber band the most ? Why ?