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32 Cards in this Set
- Front
- Back
what is a force, and what id the difference between a balanced and unbalanced force? |
A force is a push or pull. An unbalanced force occurs when the forces acting on an object are not equal. A balanced force occurs when the forces acting on an object are equal.
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how do we describe a force? |
By how strong they are and the direction in which they act
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when can forces be added together? |
only when two object acting on the same object in the same direction can be added together.
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what effect do balanced and unbalanced forces have upon an object? |
unbalanced= cause object to stop moving, stop moving, or change direction
balanced force= will never change the motion of an object. |
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be able to draw a diagram of a balanced and unbalanced force? |
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what are all changes in motion caused by? |
force |
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what is a newton (N) a unit of, and what is it equal to? |
a newton is the unit for force. 1N is equal to 1kg
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what is friction? |
the force that one surface exerts on another when the surfaces rub together.
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what are the 4 types of friction, and when do each occur? |
- Static friction acts on objects that are not moving, because you must use extra force to start the motion.
Sliding friction is when 2 solid surfaces slide over each other. Rolling friction when an object rolls over a surface Fluid friction when an object moves through a fluid |
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what might be used to reduce sliding friction? |
change sliding to fluid
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what determines the strength of friction? |
the types of surfaces involved and how hard the surfaces push together |
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If the friction on an object decreases, what happens to the force needed to move that object? |
a rough surface is needed to produce greater friction |
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what does the law of universal gravitation state? |
the force of gravity acts between all objects in the universe
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what determines the strength of gravity? |
the masses of distance between 2 objects
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what is weight? |
the force of gravity on a person or object at the surface of a planet
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describe each of newton's 3 laws |
-1st law: an object at rest will stay at rest, an object in motion will stay in motion unless acted upon by an unbalanced force
-2nd law: the net force of an object is equal to the product of its acceleration and mass -3rd law: if one object exerts a force on another object, then the 2nd object exerts a force of equal strength in the opposite direction back on the 1st object |
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what is inertia? |
the resist of any change in motion
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define mass |
the amount of matter in an object
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how does mass effect inertia? |
the amount of inertia an object has depends on its mass
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what are action/reaction forces, and why don't they cancel each other out? |
one object exerts a force on another object, then the 2nd object exerts a force of equal strength in the opposite direction back on the 1st object
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how do you changed acceleration? |
increasing the force, or decreasing the mass
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why does an object bounce when you drop it? |
action/reaction forces |
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what do momentum,acceleration, and velocity have in common? |
they are described by their direction and magnitude
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what do you mean when you say "momentum is conserved?" |
the total momentum of the objects in an interaction is the same before and after the interaction. (this is considered when no outside forces are involved) |
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what is free fall? |
when the only force acting on an object is gravity
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what is the acceleration due to gravity? |
9.8 m/s 2
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what does an object, in free fall, do until it reaches terminal velocity? |
it will experience fluid friction or air resistance
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what is air resistance and how does surface area affect it? |
a type of fluid friction, surface area increases air resistance
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define satellite |
an object that travels around another object
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what does a centripetal force do? |
causes objects to move in a circular path
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describe a satellite's movement |
satellites follow a circular path because they are moving forward while gravity pulls it down
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what is geosynchronous orbit? |
a object that orbits earth every 24 hours
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