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62 Cards in this Set
- Front
- Back
- 3rd side (hint)
What is motion?
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Motion is when an object changes position over time when compared with a reference point.
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What is speed?
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The rate at which an objects moves.
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What is velocity?
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The speed of an object in a particular direction.
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What is acceleration?
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The rate at which velocity changes.
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What is force?
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Force is simply a push or pull.
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What is a newton?
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Newton is a unit in which force is measured by.
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What is net force?
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Net force is the force that results from combining all the forces exerted on an object.
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What is friction?
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Friction is a force that opposes motion between two surfaces that are touching.
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What is gravity?
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Gravity is a force of attraction between objects that is due to their masses.
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What is mass?
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Mass is the amount of matter in an object, and its value does not change.
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To determine if an object is in motion, compare its position over time to a __________ point.
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reference
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Can a moving object be used as a reference point?
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Yes, because if you were on a hot air baloon which is a moving object, you could watch a flying bird overheard, and see it was changing position to your moving balloon.
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_______ is the rate at which an object moves.
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speed
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How fast an object moves depends on the distance traveled and the _______ taken to travel that distance.
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time
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The SI unit for speed is _____.
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m/s (meters/second)
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How do you caculate average speed?
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total distance/total time
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Velocity has speed and ________.
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direction
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To find the resultant velocity, add velocities that are in ________ directions. Subtract velocities that are in __________ directions.
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same;different
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How do you calculate acceleration?
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final velocity-starting velocity/time it takes to change velocity
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Another name for acceleration in which velocity increases is _______ accleration.
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positive
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Negative acceleration in which velocity decreases is called __________.
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deceleration
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How can you recognize acceleration on a graph?
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Velocity increases as time passes.
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True or False?
All forces have size and direction. |
True
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True or False?
A force is a push or a pull. |
True
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True or False?
Forces are measured in liters. |
False
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True or False?
You can exert a push force without there being an object to receive the force. |
False
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Forces are unbalanced when the net force is not equal to __________.
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zero
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To start or change the motion of any object, you need an _________ force.
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unbalanced
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balanced or unbalanced?
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Forces are balanced when the net force applied to an object is __________ zero.
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equal to
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less than, greater than, or equal to
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What force is responsible for the painful difference between sliding on grass and sliding on pavement?
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The force that is responsible for this is friction.
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True or False?
Friction occurs when the hills and valleys of 2 surfaces stick together. |
True
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Pavement creates more friction than grass. Why is that?
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Pavement is rougher than grass.
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True or False?
Friction is affected by the amount of surface that is touching. |
False
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What kind of friction is this?
A hockey puck crossing an ice rink. |
Sliding friction
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What kind of friction is this?
A crate resting on a loading ramp. |
Static Friction
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What kind of friction is this?
Wheeled cart being pushed |
Rolling Friction
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What kind of friction is this?
Air rushing past a speeding car |
Fluid Friction
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Static friction is at work if you try to drag a heavy suitcase along the floor and the suitcase _________.
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Doesn't move
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moves or doesn't move
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As soon as an object starts moving, static friction __________.
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disappears
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increases or disappears
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How does friction harm the engine of a car?
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It increases temperature and wears down parts.
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Why do you need friction to play sports?
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If there was no friction, you would not be able to pick up a ball or even run.
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What are some ways to reduce friction?
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Use a lubricant, make rubbing surfaces smoother, change sliding friction to rolling friction.
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The force of attraction between two objects due to their masses is the force of _________---.
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gravity
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Does all matter experience gravity?
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Yes, because matter has mass and gravity is the result of mass.
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The force that pulls you toward your pencil is called the __________ force.
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gravitational
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Since all objects are attracted to each other due to gravity, why can't you see the objects moving toward each other?
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The mass of most objects is too small to make an attraction.
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How are objects around us affected by the mass of the Earth?
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The objects on Earth and the mass of Earth have attraction because of Earth's large mass equals up to a large gravitational gorce.
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What did Newton figure out about the moon and a falling apple.
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There was an unbalanced force on the apple to make it fall, just liek the moon, except it needs the force to keep it moving in a circle.
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Newton's law of universal gravitation describes the rlationships between....
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distance, mass, and gravitational force
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Which objects are subject to the law of universal gravitation?
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Satellites, water, frogs, and stars.
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True or False?
If the distance between the objects are the same, the gravitational force between two feathers is greater than the gravitational force between two bowling balls. |
False
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If two objects are moved _________ each other the gravitational force between them increases.
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toward
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away from or toward
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Why doesn't the sun's gravitational force pull you off the Earth?
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The sun is very far away.
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What would happen to the Earth and other planets in the solar system without the sun's gravitational gorce?
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The planets would not stay in orbit around the sun.
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The strength of the gravitational force exerted by an object depends on the ________ of the object. THe measure of the Earth's gravitational force on an object is the object's _______.
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mass;weight
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Mass or Weight?
Different on the moon |
weight
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Mass or Weight?
expressed in newtons |
weight
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Mass or Weight?
measured in grams |
mass
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Mass or Weight?
measure of gravitational force |
weight
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Mass or Weight?
Value doesn't change |
mass
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Mass or Weight?
Amount of matter in an object |
mass
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True or False?
On Earth, mass and weight are constant which means they are the same thing. |
False
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