1.9 describe the effects of forces between bodies such as changes in speed, shape or direction

Forces can affect objects in 3 different ways:

• Increase or decrease the speed of an object:

If the forwards force (e.g. thrust) is bigger than the backwards force (e.g. friction) the object will accelerate

If the forwards force is smaller than the backwards force the object will decelerate  

If balance forces act on the object the movement will not change (this does NOT mean it won't move). They cancel each other out.

• Squash, stretch or change the shape of the object

If you hang a weight from an elastic band, the force applied will change the shape of the elastic band and stretch it.

• Change the direction of the object

When you through a ball upwards the force is moving upwards, however then the force of the object's weight becomes bigger than the initial thrust and it changes direction, fall back down to the ground