In Class with Dr. Prince: A Deeper Look At Different Forces

Sunday, March 17, 2013

A Deeper Look At Different Forces

How do you know if an object is moving?

The quickest and easiest way to determine if an object is in motion is to decide whether its position has changed.

What causes a change in motion?

Unbalanced forces do! When the forces around an object are equal, we call it balanced force. This means that the object is not moving. However, if one force becomes greater than another than we call it an unbalanced force. This unbalanced force causes the object to move in the direction of the greater force.

So are there other forces acting on the mouse? Yes there are! Let's go through them all first.
Applied force (FA) --> the force being applied to an object
Gravitational force (FG) --> the force gravity exerts on an object
Normal force (FN) --> the force that is equal and opposite of the gravitational force; supports the object that it is in contact with
Frictional force (FF) --> the opposing force

What is the role of inertia in all of this?

Inertia is an objects ability to resist change in its motion. The more mass an object has the greater inertia it has. In other words, if I try to push the mouse on a mouse pad it will move without too much effort because it has little inertia. A motionless elephant on the other hand has a greater mass and that means its inertia is greater too. It will be much harder to move this elephant because of its inertia (resistance to change its motion--remaining still).

Newton's 1st Law (Law of Inertia) - an object in motion remains in motion and an object at rest remains at rest until a force acts upon it.

This simply means that an object that is moving will keep moving unless a force stops it and an object that is not moving will begin to move once an applied force changes its position.

This week we will spend some time just understanding these forces. Don't forget to bring your critical eye to the classroom!