# ForceIdea

OP4

A force is that which causes motion of an object to change.

describe motion of an object

Common everyday examples of forces include to push and pull.

A car moves, what provides the force for the car?

A ripe apple falls from its node on a tree, what causes its motion?

A fridge door snaps shut, what caused the extra motion?

A man from England, named Isaac Newton, carefully studied the mechanics of nature, he identified gravity and calculates its value.

He also did lots of other work in the mechanics and optics fields of physics. In 1687 he published a great book of physics, which in english means the Principles. In this book he formulated the 3 rules of the nature of forces.

Newton's First Law states that

an object at rest tends to stay at rest and that an object in uniform motion tends to stay in uniform motion

unless acted upon by a net external force.

Newton's Second Law states that

an applied force,  , on an object equals the rate of change of its momentum, , with time

Newton's Third Law states that

for every action there is an equal and opposite reaction

recall that the newton is the unit of force,

due to all his fantastic work in this field 1kgms-2 is also called 1 Newton, more often written as 1N.

What does that mean ?

Well a force of 1N is can also be considered 1kgms-2, a one newton force would give a 1kg mass an acceleration of 1ms-2.

and describe forces and their effects

so in short a force causes motion (or a moving body to come to a stop), give different examples of different things causing (or stopping) movement of objects.

When we kick, throw, hurl something threw the air we only provide the force while we are in contact with the object.

some force ideas here explained.

http://teachers.guardian.co.uk/teacher-resources/2048/Balanced-and-unbalanced-forces