How can we measure forces?

"There are many different types of forces. Some work in contact with objects, such as friction, air resistance and water resistance.  Others work at a distance, such as magnetism and gravity and these forces are called non-contact forces. Friction is a force which opposes motion between moving surfaces in contact. The size of this force depends on the properties of the surfaces, (for example, the roughness.)

Here is a video to help you understand friction: www.bbc.co.uk/education/clips/z2kc87h

We can measure forces using Newton metres. Here is a picture of some.

The hook on the end is attached to the object being pulled and the force of the pull is measured using the scale. The scales are different depending on the size of the force (or pull) on the object. It is important to chose the correct scale of Newton metre to match the size of the force you are measuring. The scales are indicated by the colours of the Newton metre. There are 2 scales on a Newton meter, grams and Newtons. Grams is the measurement of mass but we will be using Newtons which is the unit of force.

Click here to link to information about Sir Isaac Newton who discovered gravity, you will enjoy the video. www.bbc.co.uk/education/clips/zcc9wmn