Simple Machines and Mechanical Systems

Which of these is not a simple machine?

• Scissors

• Screw

• Wheel and axle

• Pulley

What is mechanical advantage? 

• Basic accuracy training. 

• A measure of how strong the force of gravity is between two objects.

• When a machine reduces the chances of effectiveness.

• A measure of how much easier the machine makes the work.

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NGSS.MS-ETS1-2

What is effort (input) force?

• the force one exerts on a machine

• the force which an effort force must overcome in order to do work on an object via a simple machine.

• the force the machine exerts on a object

• the output work times the input distance

A machine with a mechanical advantage greater than 1:

• multiplies the input force so the machine would be good to help move heavy objects.

• does not multiply the force, but increases distance and speed.

• has no effect on speed or effort force

A machine with a mechanical advantage of less than 1:

• multiplies the input force so the machine would be good to help move heavy objects.

• does not multiply the force, but increases distance and speed.

• does not affect distance or speed

A machine with a mechanical advantage equal to 1:

• multiplies the input force so the machine would be good to help move heavy objects.

• does not multiply the force, but increases distance and speed.

• does not affect distance or speed

The efficiency of a machine can be increased by reducing __________________________. 

• effort

• resistance friction

• fulcrum

• friction

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NGSS.MS-ETS1-1

Why can mechanical efficiency never be 100%?

• No machine is strong enough.

• Machines are too big to allow for 100% efficiency.

• It can be 100%.

• Some energy is lost in the form of heat/sound due to friction.

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What happens to the overall efficiency of a machine as I add more machines?

• For each simple machine you add, the overall efficiency increases because it gets faster.

• For each simple machine you add, the overall efficiency decreases.

• The overall efficiency is divided in half for every simple machine you add.

• There is no connection.

What do we call the gear connected to the input power source, such as a motor?

• Driven Gear

• Bigger Gear

• Smaller Gear

• Driving Gear

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