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44 Cards in this Set
- Front
- Back
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In order for work to occur, __________. |
The object has to move in the direction the force is applied. |
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Work = ____________. |
Force x distance. |
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What is power? |
Power is the rate work is done at. |
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Power = ___________. |
Work / time |
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What is work measured in? |
Joules. |
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What is force measured in? |
Newtons. |
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What is time measured in? |
Seconds. |
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What is power measured in? |
Joules per second, (joules/second) |
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What is the definition of a machine? |
A machine is an instrument that makes work easier. |
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What is the term for the work you put into machines? |
Work input. |
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What is the term for the work that comes out of machines? |
Work output. |
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What needs to happen with the resistance force in order for the desired result to be achieved? |
The output force needs to overcome the resistance force. |
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What happens if the resistance force is too great? |
The output force cannot overcome it. |
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Which one is true? a. Machines can increase work put in. b. Machines can make work easier. |
B is true. |
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What two things can machines do to make work easier? |
They can change the amount of force put in or they can change the direction of the force. |
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What do simple machines do to the effort force? |
They increase or multiply the effort force. |
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What is mechanical advantage? |
The number of times a machine multiplies the effort force. |
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Mechanical advantage = ____________ |
Resistance force / effort force |
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What is a lever? |
A lever is a straight part that pivots around a fixed point. |
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Where are the parts of a 1st-class lever? |
In a 1st-class lever, the fulcrum is between the effort force and the resistance force. |
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Where are the parts of a 2nd-class lever? |
In a 2nd-class lever, the resistance force is between the fulcrum and the effort force. |
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Where are the parts of a 3rd-class lever? |
In a 2nd-class lever, the effort force is between the fulcrum and the resistance force. |
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What changes with a 3rd-class lever? |
In a 3rd-class lever, the effort force is not multiplied. The distance moved is increased. |
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What is the formula for calculating the mechanical advantage of a lever? |
Distance of effort force to the fulcrum / distance of resistance force to the fulcrum |
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An inclined plane does NOT _________. Instead, it _____________________. |
Inclined planes do not change the amount of work necessary. Instead, they reduce the effort force. |
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Give two examples of an inclined plane. |
Ramp, waterslide, etc |
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Give two examples of a lever. |
Door handle, fork, etc |
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Give two examples of a pulley. |
Flagpole, blinds, etc. |
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What does a pulley consist of? |
A pulley consists of a rope wrapped around a grooved wheel. |
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What does a fixed pulley change? |
A fixed pulley changes the direction of the effort force. |
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Regarding the pulley: The distance the object is pulled = ? |
The distance the object is pulled = the distance it travels. |
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What are the two types of pulleys? |
Fixed and movable. |
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The movable pulley is _____________ and _______________. The __________ must be applied over _____________. |
- It is movable and attatched to the object. - The effort force must be applied over longer distance. |
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What is a pulley system? |
A pulley system is the term for more than one pulley in the same machine. |
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How can you find the mechanical advantage of a pulley? |
The number of ropes pulling on the resistance force is equal to the mechanical advantage. |
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Give two examples of the wheel and axle. |
Car wheels, tap (handle), etc |
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What is the axle? |
The axle is the part by which the wheel turns. It is smaller than the wheel. |
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When effort force is applied to the wheel, it's _______________ and ______________. |
When effort force is applied to the wheel, it's multiplied at the axle and overcomes the resistance force. |
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The mechanical advantage of the wheel and axle is always _______________. |
Greater than one. |
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What is the formula for calculating the mechanical advantage of the wheel and axle? |
Wheel radius / axle radius. |
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What is the formula for calculating the MA of an Inclined Plane? |
Length of slope / height of slope. |
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What is the formula for calculating the MA of a wedge? |
Wedge thickness / wedge length |
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Give two examples of the wedge. |
Axe, shovel, etc |
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What does the inclined plane reduce? |
The inclined plane reduces the effort force. |
