Term
| Describe a situation when a force does/produces work. |
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Definition
| If the force produces motion of an object in the same direction as the force, work has been done on the object. |
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Term
| What is the relationship between work and power? |
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Definition
| An increase in power can do more work, or do it faster. |
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Term
| Give two ways you can increase power: |
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Definition
1. Produce the same amount of work in less time.
2. Do more work in the same amount of time. |
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Term
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Definition
Work is force multiplied by the distance an object moves.
W = f x d |
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Term
| What is the official SI unit of work? |
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Definition
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Term
| What is the "meaning" of a joule? |
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Definition
| when an object is moved 1 meter (distance) using a force of 1 N. |
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Term
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Definition
| The rate at at which work is completed. |
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Term
| What is the SI unit of power? |
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Definition
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Term
| What is the "meaning" of a watt? |
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Definition
| when work is done at the rate of 1 joule per second. |
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Term
How many watts is 1 horsepower equal too?
(not on test, just interesting) |
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Definition
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Term
What is the history behind the term "horsepower"?
(not on test, just interesting) |
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Definition
| James Watt was looking for a way to compare engines to the efforts of a horse. |
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Term
[image]
Is work being done while he holds the weight above his head? Why or why not? |
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Definition
| No because the weights are not moving. |
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Term
| You exert a vertical force of 7 newtons to lift a box to a height of 1.0 meter in a time of 2.0 seconds. How much power is used to lift the box? |
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Definition
| 36 W , make sure to show your work and use all units. |
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Term
| When the floor "supports" you, with a normal force, is it doing work? Why or why not? |
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Definition
| No, because you are not moving! |
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Term
| Machines can make easier by doing one of 3 things. Name the three things a machine might change. |
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Definition
They change the size of a force needed,
the direction of a force,
or the distance over which a force acts. |
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Term
| How is the work input related to the work output in a machine? |
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Definition
| Because of friction, the work done by a machine is always less than the work done on the machine. |
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Term
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Definition
| A machine is an object that changes the size, direction or distance over which the force is applied. |
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Term
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Definition
the amount of force applied TO the machine
(Hint: I= I am pushing/pulling where) |
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Term
What is input distance?
(Not on test) |
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Definition
| The distance over which the input force is applied. (How far you push or pull) |
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Term
What is input work?
(Not on test) |
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Definition
| The amount of work you put into a machine. This is calculated by taking the input force and multiplying by the input distance. |
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Term
What is output force?
(Not on test) |
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Definition
| The amount of force that the machine produces. |
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Term
What is output distance?
(Not on test) |
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Definition
| The distance over which the machine exerts a force. |
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Term
What is output work?
(Not on test) |
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Definition
| The amount of work performed by the machine. |
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Term
True or False:
A machine allows you to do less work and still produce more work. |
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Definition
| False, a machine will never produce more work that you put into it. |
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Term
| How does the actual mechanical advantage of a machine compare to its ideal mechanical advantage? |
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Definition
| The actual MA is always less than the ideal MA. |
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Term
| Why is the efficiency of a machine always less than 100 percent? |
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Definition
| Because friction will always reduce the actual mechanical advantage of a machine. |
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Term
| What is the mechanical advantage of a machine? |
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Definition
| MA is the number of times a machine multiples the input force. So if the machine makes your force of 2N become 4N of output force, its MA is 2 (2x greater) |
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Term
| What is the Actual Mechanical Advantage of a machine? |
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Definition
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Term
What is Ideal Mechanical Advantage?
(Not on test) |
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Definition
| Ideal Mechanical Advantage is the mechanical advantage of a machine, minus any friction. |
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Term
What is the efficiency of a machine?
(Not on test) |
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Definition
| The percentage of the work input that becomes work output is the efficiency of a machine. |
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Term
| Name the six types of simple machines. |
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Definition
| Lever, Pulley, Screw, Wedge, Incline Plane, Wheel and Axle |
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Term
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Definition
| A simple machine of a rigid bar with a fixed point. |
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Term
Draw a lever and label the input force, input distance, fulcrum, output force, and output distance. |
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Definition
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Term
How many types of levers are there? Draw a picture of each: |
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Definition
| There are 3 types of levers.
[image] |
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Term
How many types of pulley systems are there? Draw a diagram of each: (not on test) |
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Definition
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Term
| What is a compound machine? |
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Definition
| A machine made up of 2 or more different types of simple machines. |
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