ENERGY FORCE WORK Energy Ability to do work

ENERGY - FORCE - WORK

Energy Ability to do work

Potential Energy § Stored energy held in readiness state

Kinetic Energy §Energy in motion. Depends on the mass + Speed of an object.

A force is any push or pull on an object.

The unit of measurement force is Newtons

The tool used to measure weight or force is a spring scale.

Net Force The overall force acting on the object.

Opposite forces are BALANCED FORCES if their effects balance each other and DO NOT cause a change in motion. They have a net force of zero. If one force is stronger, then they are UNBALANCED and cause a change in motion.

1000 Newtons Balanced or unbalanced? Forces equal or not equal? Is there motion? What is the net force?

200 Newtons 100 Newtons Balanced or unbalanced? Forces equal or not equal? Is there motion left or right? What is the net force?

When a force is exerted that moves an object you do work.

The force must be in the same direction as the object’s motion for WORK to have happened.

. If NO movement takes place = NO WORK has been done!

Work can be calculated using the following formula: W = F X d Work = Force X distance

The unit of measurement for work is Joules.

How much work is done if a force of 20 Newtons moves a box 4 meters? 20 N 4 m

How much work is done if a force of 60 Newtons moves a box 5 meters? 60 N 5 m

How much work is done if a force of 30 Newtons moves a box 3 meters? 30 N 3 m

The change in position of an object… Motion

Device that makes effort seem easier… Machine

Force you exert on a machine… Input force

Force exerted by a machine… Output force

Inclined plane: Flat surface that slopes.

Less input force needed to move an object, but it must be moved over a greater distance.

Examples:

Pulley: Wheel with a rope, cable or chain around it.

Can change the direction and the amount of the input force by increasing the distance over which the force is applied.

Examples: