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20 Cards in this Set
- Front
- Back
What is a force? |
A push, pull or twist. |
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List some things forces can do? |
Start an object moving Speed an object up Cause an object to change direction Stop or slow and object |
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These are examples of what kind of instrument used for measuring forces? |
Springbalance The larger the pulling force, the more the spring is stretched and the higher the reading on the scale. |
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The forces acting on this bike are _________? |
Balanced (Doesn't always mean an object is stopped. It could be travelling at a constant speed.) |
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The forces acting on this bike are_________ ? |
Unbalanced When forces become unbalanced, the motion of the object will change. |
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What is inertia? |
The tendency of any object to resist any change in its motion (stay still). |
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True or false? |
True - E.g. It takes a smaller force to stop a pebble rolling than a boulder. |
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What is friction? |
The force that slows things down. Friction occurs whenever two objects are in contact. |
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Explain Newton's 1st Law? |
Objects that are moving, will continue to do so unless a force acts on them. |
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Give some examples of why friction is important? |
It slows things down, stops them and provides grip.
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True or false? |
True |
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What two things affect friction? |
1) How rough the surfaces in contact are |
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Give some examples of unwanted friction. |
Friction causes heat - makes machines less efficient/wastes energy. |
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List some ways to reduce friction. |
Oiling or lubricating a machine to reduce friction. |
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What is gravity? |
All objects attract each other. This force of attraction is called gravity. |
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What is mass? |
The amount of matter in an object (its size). |
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What is weight? |
The name given to the pulling force of gravity on an object. Your weight depends on your mass and the strength of the gravitational field of the planet you are on. |
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List things that may affect the stability of a structure. |
Wind Rain Extreme heat |
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True or false? |
False |
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What is terminal velocity? |
When the forces acting on an object are balanced and the object falls at a constant speed it has reached it's terminal velocity. |