Motion. Definition a change of position

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1 Potential energy Definition stored energy an object has because of its position Characteristics the higher up an object is, the greater its potential energy Example book sitting on the desk

2 Kinetic energy Definition the energy an object has because it is moving Characteristics the greater the speed and mass of the object the greater its kinetic energy Example falling book

3 force Definition a push or pull that has a size and direction Characteristics Forces can make an object start moving, stop moving, change speed, or change direction Example exertion

4 Net force Definition sum of all forces acting on an object Characteristics if you and a friend are pushing a box together you add the forces, if you are pushing in one direction and your friend in another subtract the forces Example tug of war

5 Motion Definition a change of position Characteristics you know motion when you see it, when something goes from point a to point b it moved or was in motion Example walking

6 Balanced forces Definition forces that cancel each other out because they are equal and acting in opposite directions Characteristics produces no change in the motion of an object; if the object is sitting still it will remain still and if it is moving it will maintain its speed and direction Example equal force

7 Unbalanced force Definition forces that are unequal in size or direction and that change an object s motion Characteristics net force greater than zero are unbalanced forces, they produce a change in motion; motionless objects start moving and moving objects change speed and/or direction Example unequal

8 newton Definition SI unit of force Characteristics it takes 45N of force to lift the average cat! Example force unit

9 Air resistance Definition - frictional forces placed upon an object as it moves through the air causing it to slow down Characteristics even though it is invisible, anything moving through air must push it out of the way, two objects cannot occupy the same space at the same time, Example colliding

10 speed Definition distance traveled divided by the amount of time that is needed to travel that distance Characteristics 120 miles divided by 3 hours equals 40 miles per hour. Example how fast

11 Average speed Definition the total distance traveled divided by the total time taken Characteristics the unit is miles per hour; m/hr, or kilometers per hour; km/hr Example 65 m/hr

12 acceleration Definition change in velocity divided by the amount of time over which the change occurs; can take place when an object changes speed, direction, or both Characteristics in science acceleration means speeding up or slowing down or changing direction Example movement

13 Work Definition when a force is used to move an object through a distance Characteristics the greater the force and the greater the distance the object moves, the more work that is done Example moving an object

14 Simple machine Definition a tool that makes it easier to move an object Characteristics a tool that makes work easier, a simple machine let you use less force to move an object; the amount of work you do doesn t change, the amount of force you apply and the distance you apply to it changes! Example gadget/tool

15 Inclined plane Definition a simple machine made of a flat, sloping surface Characteristics a ramp! It is the only simple machine that does not move, objects are moved over it in order to raise them, less force (than lifting object straight up) but greater distance (all the way up the ramp) to the object Example bank

16 pulley Definition a simple machine made of a wheel with a rope or chain wrapped around it Characteristics used to lift heavy objects, it can reduce the force that is needed to lift the object or it changes the direction of the force Example exercise equipment (rowing machine)

17 direction Definition - The path that an object is moving or facing Characteristics direction is important when talking about forces, we have to know the direction of the force Example bearing

18 position Definition - the place, situation, or location of a person or thing Characteristics precisely where an object is located Example - location

19 Conservation of Energy Definition - Energy cannot be created nor destroyed; it changes from one form to another Characteristics we cannot make energy, energy just changes to an unusable form for our current technology. So do we have an energy crisis? Example change

20 Load Definition the object to be moved using a machine Characteristics using a pulley to lift a motor out of a car, the motor is the load; moving a heavy box up an incline plane, the box is the load Example moving