force and motion
Post on 14-Dec-2015
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Force and Motionhttps://www.youtube.com/watch?v=8iKhLGK7HGk
Motion
• Motion is an object changing its position over time.
• How far an object moved in a certain amount of time.
• Often shown in Miles Per Hour (MPH) or meters per second (mps).
Force
• A push or a pull• Force can be applied to an object to change
it’s motion.• Force can make an object in motion change
it’s direction
Balanced Force
• Balanced forces cause an object to stay in place.
• A table can represent a balanced force: Gravity is pulling it down while the floor is pushing up on it with equal force. The table remains still.
Unbalanced Force
• Unbalanced forces cause objects to start moving, stop moving, or change direction.
• Unbalanced forces change the motion of objects.
• 3 factors: direction of force applied, strength of the force, mass of the object.
Direction
• The direction that a force is applied will determine the direction of the motion of the object.
Gravitational Force
• “Gravity”• The attraction one object has for other
objects.
• All objects exert a gravitational force on all other objects.
• The more matter an object has, the more gravity it will have.
Friction
• A force that acts in the opposite direction of an objects motion.
• When objects touch their surfaces interact.• Moving one surface across another creates
friction. • If you rub the surface of your hands together
quickly you will feel heat, heat is created by friction.
• https://www.youtube.com/watch?v=MAqrWvkBoHk
Air Resistance
• Friction between a moving object and the air it is passing through.
• If you hold your hand out of a car window while traveling you will feel air resistance.
• Air resistance keeps race cars from going any faster.
Inertia
• An object at rest wants to stay at rest.Inertia Egg Video
Acceleration
• A measurement of how speed changes
Acceleration
Momentum
• The measure of the amount of force that it would take to stop a moving object. Due to its mass and speed.
Qualitative Description
• Properties of matter described using words.• Example: The soft chair is blue with stripes
and it smells like flowers.
Quantitative Description
• Properties of matter described using numbers.• Example: The chair has two wheels and four
legs.• Example: The toy car has a mass of 50 grams.
Conservation of Energy
• Energy cannot be created or destroyed, but can change form or be transferred from one thing to another.
Simple Machines
• Change the amount of force needed to move an object.
• Make it easier for us to do work.
Pulley
• A wheel with a groove around the middle, a rope fits into the groove and wraps around the wheel.
• Force needed to lift a weight is about half when using a pulley.
Screw
• An inclined plane wrapped around a center shaft, called threads.
• It is used by turning to pull things together.
Gear
• A wheel with teeth around the outside to connect with other gears.
• They can change the amount of force needed to move an object.
Newton
• The metric measurement of force.• 1 N = 1kg x 1m / (s x s)• One Newton is equal to the force needed to
move one kilogram one meter in one second.
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