Forces and Motion

Five Forces Studied

1. Push

2. Pull3. Gravity

4. Magnetism5. Friction

Forces and Motion

Force: a push or a pull

The amount of force you have to use to move an object depends on its mass.

Which requires more force?

orBowling ball

Why when you drop something does it always fall down?........

Gravity: force that pulls objects

toward each other

The more mass two objects have, the more gravity pulls them toward each other. Earth has more mass than the moon and so the gravity is stronger on earth.

Weight: measure of the pull of gravity on an object

Magnetism

Opposite poles (north and south) attract

pull

Like poles (south and south or north and north) repel

Iron and Steel are attracted to magnets

Friction is a force!

Friction is a force that occurs when 2 surfaces oppose each other.

Remember the activity of the same ramp, same marble however the floor types are different. Why did the marble travel different distances????

Friction – wood and tile are smoother and thus have less friction and will then allow the marble to travel farther. The carpet is rougher and has more friction, and slows down the marble faster.

Friction can be ….

Keep wheels on the road.

Applying brakes

Rubbing hands together

Motion: a change in position

Every motion is started by a force and every motion is stopped by a force. A force can also change the position of an object.

Change the direction of a ball by applying another force on the ball.

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Not all forces stop or start a motion. If one student is pushing on one end of a box and another student is pushing on the opposite end of a box, the forces are balanced and the box doesn’t move. There is no motion.

Equal or Balanced Forces

Speed: Measure of how fast something moves over a certain distance.

To calculate speed: Speed = distance you went/ time it takes to get there

Work: measure of force it takes to move an object a certain distance

Work = force needed to move object (newtons) a certain distance

Pushing against a wall is NOT work.

The amount of matter that an object has.

Mass

A measure of the amount of force needed to move an object a certain distance.

Work

A tool used for measuring mass.

Balance

A measure of how fast something moves over a distance.

Speed

Any push or pull

Force

Equal forces on an object that cancel out

Balanced Forces

A device used for measuring weight and force need to move an object.

Spring Scale

A change in the position or place of something

Motion

A force that pulls objects toward the Earth.

Gravity

The location of that place or object

Position

A force - rubbing of one object against another

Friction

The measure of the force of gravity on an object.

Weight

The natural force produced by a magnetic field.

Magnetism

A unit that is a measure of force.

Newton

Forces that are not equal in size and direction

Unbalanced Forces