What are Forces

What are forces?

A force is a push or pull. Many actions, such as squeezing, lifting and pressing, involve pushes and pulls. When you squeeze a tube of toothpaste or press a lift button, you are applying forces on these objects by pushing on them. When you put on your socks or lift your bag, you are applying forces on them by pulling them.

Example of Forces:

• You pull on the door to open it.
• You push your math book to the far side of the desk.
• The math book falls off the edge and gravity pulls it to the floor.
• You pick up the math book and put it back on the desk.

How do we know that a force exists?

We know that a force exists by observing its effect on objects when it interacts with them.

Properties of Forces:

• A force can make a stationary object move.
• A force can make a moving object speed up or move faster.
• A force can change the direction of a moving object.
• A force can slow down a moving object.
• A force can change the shape of an object.

There are different types of forces such as magnetic force, gravitational force (gravity), upthrust ad frictional force (friction).

The size and direction of a force:

The size of the force:

Forces can be weak or strong. The forces of earthquakes and cyclones are strong enough to cause great damage. In the laboratory, the size of a force can be measured by a forcemeter or spring balance in the unit newton (N).

A spring stretches when it is pulled and compresses when it is pushed. The larger the force, the more the spring is stretched or compressed. For this reason, springs can be used to measure forces.

Direction of a force:

The arrows show four different forces acting on the aeroplane. The direction of each force is indicated by the arrowhead and the size of each force by the length of the arrow.

From the diagram, we can see that more than one force can act on an object. The lift acts upwards, in the opposite direction of the weight of the aeroplane which pulls it downwards. The drag (air resistance) acts in the opposite direction of the thrust which moves the aeroplane forward. 

Basically a force is exerted on one object by another. The idea of a force is not limited to living things or non-living things. All objects (living and non-living) can apply a force on or to another object; also all objects (living and non-living) can be affected by forces.