Mechanical Systems

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.

Tags

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

Tags

NGSS.MS-ETS1-1

NGSS.MS-ETS1-2

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

To increase the mechanical advantage of a lever

• make sure the fulcrum is in the middle of the lever

• move the fulcrum closer to the load

• move the fulcrum closer to the person

• use a bigger fulcrum

Jeff is a landscaping contractor and lifts a rock weighing 600 Newtons by wedging a board under the rock. Jeff weighs 150 Newtons and puts all of his weight on the lever. How much mechanical advantage did the lever provide to Jeff in lifting the rock?

• 0

• 2

• 4

• 0.25

Tags

NGSS.MS-PS2-2

What is the mechanical advantage of the lever shown?

• 10

• 0.1

• 50

• 250

What is the efficiency of the following simple machine?

• 85%

• 3%

• 33%

• 39%

Tags

NGSS.MS-ETS1-2

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

• effort

• resistance friction

• fulcrum

• friction

What does friction produce that reduces efficiency?

• heat

• water

• energy

• work

Tags

NGSS.MS-PS2-2