Force and Motion

Lesson 10

•Motion occurs when an object changes its position, or moves from one location to another.

•When force is applied to an object, it causes it to move.

•Position is where something is located.

•Distance is the length the object moves.

•Speed is how fast an object moves in a specific amount of time.

•Think about serving a volleyball, or kicking a football…

•You provide the force to make the balls move, and fly through the air

•Then gravity pulls it down

•Once the ball hits the ground, it will roll.•The ball stops moving because of friction, the rubbing of the volleyball or football against the ground.

• If there were no friction to slow down the ball, it would keep rolling forever – or until some other force stopped it.

•All changes in motion are caused by a force of some kind.

•To start an object moving, it requires some force.

•Once moving, an object keeps moving at the same speed and direction until some new force changes of stops it.

•In outer space there is no friction to slow down motion. Objects only come to a stop when they come into contact with some other force.

http://www.youtube.com/watch?v=A6nkbgC_eDY

• Push-and-Pull Force

• Gravity

• Magnetism• Friction

•Push-and-Pull Force is when a moving object pushes or pulls at another object. This force requires direct contact.

•Some motion from the first object transfers to the second object through their contact.

http://www.youtube.com/watch?v=7deV22aWESc&feature=related

• Gravity works without direct contact.

• Gravity is the force of attraction between any two objects. As an object falls to Earth, gravity makes its speed increase.

• The pull of gravity gives objects their weight. Gravity increase with the mass of objects. It decreases as the objects move farther apart.

• The farther the magnet is from the metallic object the less the force is. The strength of the magnetic force around a magnet is known as its magnetic field.

•Magnetism pulls many types of metal objects towards a magnet. This is force works without direct contact.

•Every magnet has two sides, known as poles.

•The north pole (shown as N) of one magnet will attract the south pole of another magnet (shown as S).

•The two north poles or two south poles will repel or push away from each other.

•Friction is the force created when two things rub against each other. This force requires contact between the objects.

•As two objects rub, they grind and drag against each other. This rubbing and grinding slows their motion and produces heat.

•On Earth, moving objects face friction from both the air and ground. Eventually, they stop moving unless some other force is applied to keep them going.

•The amount of friction depends on the type of surfaces rubbing together. The more rough the surfaces the greater the friction.

• To reduce friction in machines oil and other lubricants are used. These make the surfaces smoother.

•Not all friction is bad. Friction can be very helpful. An example is when running on wet floor, to little friction can make you slide. Friction is needed to get a grip while moving.

•Sliding into a base during a baseball game works by friction. As you slide your body rubs against the ground.

http://www.neok12.com/php/watch.php?v=zX66536e747d7a514265766b&t=Types-of-Forces

http://www.neok12.com/quiz/FORCES04

Position- is where an object is located.

Motion- occurs when an object changes its position.

•it moves from one location to another.

Speed- is how fast an object is moving.

•Measures the distance of an object as it travels in a given amount of time, such as miles per hour.

•The length it travels is known as distance

Force- is what makes an object start moving or change its speed or direction.

Push or Pull- The force created when an object pushes or pulls another object.

PUSH EXAMPLE- mowing the lawn; grocery shopping cart.

PULL EXAMPLE- tug of war; opening a drawer

Gravity- The force pulling objects to the Earth. The force of gravity increases with the mass of the object.

EXAMPLE- Sky diving ; throwing a ball up in the air and it dropping to the floor.

Magnetism- A force from a magnet, pulling at some metals.

EXAMPLE- magnets on the refrigerator.

Friction- A force on Earth created by the rubbing of two surfaces that slows down their motion and produces heat.

EXAMPLE –rubbing your hands together.