# Physics P2.2

?
• Created by: juddr12
• Created on: 09-04-14 11:32

P2 2.1

Newtons measure force.

All objects exert equal and opposite forces. These are also called 'action and reaction forces'. For example, if a book is placed on a table, then the book's force vertically down is the same as the table's force holding the book up.

P2 2.2

A resultant force is all of the forces acting together (adding them together). It will only equal 0 if the object is resting or it is moving at a constant speed without acceleration. If it does not equal zero, it is either acceleration or deceleration.

P2 2.3

Resultant force = mass (in KG) x acceleration (in m/s2)

The bigger the mass of an object, the more force it takes to move it.

P2 2.4

The faster an object is moving, the harder it is to decelerate it. This is risky for real life experiences in cars when you have to stop suddenly. There are TWO distances that are referred to in such cases: braking and thinking distance (with stopping distance being the sum of the both). Braking distance is the distance it takes to fully stop the vehicle after you have pressed the brakes. The thinking distance is the distance it takes for the driver to realise the conditions and then hits the brakes.

P2 2.5

If an object falls, then the resultant force acting upon it is the force of gravity. The force of