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14 Cards in this Set
- Front
- Back
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_____ are devices for doing work.
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Machines
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Basic force-multiplying machines are called __ _____.
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simple machines
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Simple machines can help in three ways:
1 2 3 |
1.multiplying the force applied to them
2.changing the direction of the force 3. multiplying the speed or distance of the force |
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When we use machines, we see two factors are work:
1 2 |
1. effort
2. resistance |
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______ is the force we apply to the machine.
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Effort
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The force the machine helps us ovecome is called _____.
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resistance
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The __ ____ tells us the number of times a machine multiplies our effort.
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mechanical advantage
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The formula for mechanical advantage:
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Mechanical advantage =
resistance force/effort force |
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If a man uses 50 pounds of effort to lift 250 pounds, what is the mechanical advantage?
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250 divided by 50 = 5
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The work put into a machine is called __ ___.
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work input
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__ ___ is the product of the effort force x the distance the effort is exerted.
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work input
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__ ___ is the work received from the machine.
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work output
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The Law of Work states:
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The work put into a mahcine is equal to the work received from the machine. (without friction)
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Because of _______, work input is always greater than work output.
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friction
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