by Darien Santmyer

Created on: May 21, 2009   Last Updated: May 23, 2009

Isaac Newton's laws of motion might be difficult to understand, but hopefully after reading my article, you will have a clearer understanding of Newton's laws.

The first law is: A body persists its state of rest or of uniform motion unless acted upon by an external unbalanced force.

This means that an object will continue to 'do what it is doing' until it is 'disturbed by an outside force'. An example would be a pen on a desk. The pen will continue to do what it is doing unless a force acts on the object. Another example would be an object in a vacuum. If you apply a force to the object, it will continue to move eternally because there are no external forces to disturb it.

The second law states that: Force equals mass times acceleration or F = ma

The law itself explains itself. You first need to know the mass and acceleration of the object. An example would be an object with a mass of 15g and an acceleration of 10m/s^2 with a force of 20N acted on it.

To solve the problem, we multiply 15 by 10.

But in real life, it is not so simple. Sometimes you may not have quantities for A or M, As long as you know the value of two of the three parameters, you can solve for the other parameters algebraically F=ma, a=F/a, a=F/m.

Try to answer the problem with the formulas I gave you.

What is the mass of an object with an acceleration of 20m/s^2 when the force applied was 80N.

Newton's final law is: For every action there is an equal and opposite reaction

This law states that if a force is applied to an object, a force of the same magnitude is exerted back on you.

An example would be applying a force of 60N on a wall. The wall would exert the same force of 60N back on you.

Another example would be applying a force of 80N on a boulder. The boulder would exert a force of 80N on you. No matter what object a force is applied on, the same force is sill exerted back.

This law can be illustrated in swimming. You push the water in the opposite direction that you intent to go, and the water applies a force back on you.

This is possibly the simplest of Newton's laws, yet a fundamental one which can be observed in waves.

You should now know about Newton's three laws, but to make sure you remember them, they are:

A body persists its state of rest or of uniform motion unless acted upon by an external unbalanced force.

Force equals mass times acceleration

And finally, For every action there is an equal and opposite reaction.

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