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21 Cards in this Set
- Front
- Back
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How can you tell if an object is in motion?
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If its distance from another object is changing.
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What is the SI unit of length?
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Meter
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What is the difference between instantaneous speed and average speed?
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The average speed is the overall rate of speed an object moves at and instantaneous speed is the rate at which an object moves at a given instant in time.
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What 3 things does acceleration refer to in science?
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Increasing speed, decreasing speed, and changing direction.
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What SI unit is force measured in?
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Newton
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What two factors does the strength of the force of friction depend on?
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How hard the surfaces push together and the types of surfaces involved.
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What are the four types of friction?
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Static, sliding, rolling, and fluid.
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What two factors affect the gravitational attraction between two objects?
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Mass and distance.
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When is an object considered in free fall?
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When the only force acting on it is gravity.
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What does Newton's first law state?
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An object at rest will remain at rest, and an object moving at a constant velocity will continue moving at a constant velocity unless acted upon by an unbalanced force.
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What does Newton's second law state?
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Acceleration depends on the object's mass and on the net force acting on the object.
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What does Newton's third law of motion state?
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If one object exerts a force on another object, then the second object exerts a force of equal strength in the opposite direction on the first object.
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What does a centripetal force cause an object to do?
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Move in a circular path?
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Why don't satellites fall down to Earth?
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Because Earth is curved.
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When is work done on an object?
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When the object moves in the same direction in which the force is exerted.
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By changing which 3 factors does a machine make work easier?
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The amount of force you exert, the distance over which you exert your force, and the direction in which you exert your force.
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What are the 6 basic kinds of simple machines?
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Inclined plane, wheel and axle, wedge, screw, pulley, and lever.
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Where is the fulcrum in relation to the output force in a first-class lever?
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The fulcrum is closer to the output force.
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Where is the fulcrum in relation to the input force in a second-class lever?
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The fulcrum is farther away from the input force.
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Where is the fulcrum in a third-class lever?
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The fulcrum is wherever you put your hand.
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Does a fixed pulley or a movable pulley have a higher mechanical advantage?
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Movable pulley.
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