Term
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Definition
Change in position of an object relative to a reference point.
Direction can by up, down, north, south, etc |
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Definition
An object that stays in position
Examples:
1. Earth as a reference point for a hot air balloon
2. A building for a car's motion |
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Definition
The distance traveled during a given time
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Term
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Definition
Speed = Distance ÷ Time
Example: If a balloon travels 50 mters in 10 seconds, what is the speed?
Speed = 50 meters÷10 seconds = 5m/sec |
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Term
| Why do we find average speed instead of constant speed? |
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Definition
| Most objects do not travel at a constant speed at all times, so it is important to know average speed |
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Term
| Formula for Average Speed |
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Definition
| Average Speed = total distance ÷ total time |
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Term
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Definition
Speed of an object in a direction
An object's velocity is constant if BOTH speed and direction stay the same |
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Term
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Definition
The rate at which an object's velocity changes
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Term
| What causes objects to accelerate? |
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Definition
An object accelerates if it changes
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Term
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Definition
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Term
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Definition
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Term
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Definition
Acceleration in a circular motion
Example: Earth's rotation |
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Term
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Definition
Push or pull
All forces have a direction & size |
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Term
| What are forces measured in? |
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Definition
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Term
| Examples of forces that can't be seen |
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Definition
| Gravity pulling us towards the Earth's surface |
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Term
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Definition
The combination of all forces acting on an object
Forces acting in the same direction - add together to find net force
Forces acting in opposite direction - subtract to find net force |
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Term
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Definition
Produce a 0 N, no change in motion.
examples: books sitting on a table |
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Term
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Definition
do not have a net force of 0 N
Needed to move objects
Example: soccer player kicking a ball |
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Term
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Definition
| Forces that opposes (go against) motion between two object |
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Term
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Definition
| smoothness of a surface & the forces the objects exert |
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Term
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Definition
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Term
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Definition
| the LARGER the amount of friction |
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Term
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Definition
Friction between two moving objects
Example: moving a piece of furniture |
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Term
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Definition
| pushing the furniture across a room (more difficult) |
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Term
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Definition
Putting the furniture on wheels to move it
(easier, less friction) |
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Term
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Definition
Friction between two objects that are not moving
Example: books on a table |
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Term
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Definition
- car brakes
- between pencil and paper as you are writing
- rubber on the soles of your shoes keeping you from slipping when walking
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Term
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Definition
- engine parts breaking
- sock holes (worn away)
- erosion of topsoil for plant caused by wind and water
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Term
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Definition
Lubricants - oil, wax, grease applied to surface to reduce friction
Switching from static to sliding to rolling friction - adding ball bearings in the wheel & axel of in-line skates
Make surfaces smoother- rough bench is harder to slide across than one that has been sanded |
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Term
| Ways to increase friction |
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Definition
Make surfaces rougher - sand or salt on icy surfaces
increase the force between surfaces - sand wook quicker, push harder on the sandpaper |
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Term
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Definition
a force of attraction between obbjects due to their masses.
the force of gravity can be changed by speed, direction or both. |
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Term
| Law of Universal Gravitation |
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Definition
| There is a relationship between gravitational force, mass and distance for all objects in the universe |
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Term
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Definition
| gravitational force increases |
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Term
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Definition
| gravitational force decreases |
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Term
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Definition
| gravitational force decreases |
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Term
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Definition
| is a measure of gravitational force on an object |
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Term
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Definition
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Term
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Definition
| Amount of matter an object contains |
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Term
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Definition
| grams, kilograms, or milligrams |
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