Work, Power, Simple Machines

What is work defined as in physics?

• The force that opposes motion between two touching surfaces.

• The distance an object travels.

• The force applied on a machine.

• When a force causes an object to move in the same direction that the force is applied.

How is power related to work?

• Power is the force that opposes motion.

• Power is the distance work can cause an object to move.

• Power is how quickly work is done.

• Power is the force applied by a machine.

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

What is the mechanical advantage of a machine?

• The ratio of the input work to the output work.

• The ratio of the output force to the input force.

• The ratio of the input force to the output work.

• The ratio of the output work to the input work.

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NGSS.MS-PS2-2

What is a simple machine?

• A machine that is easy to use.

• A machine that does work with only one movement.

• A machine made up of several parts.

• A machine that requires electricity to operate.

Which of the following is an example of an inclined plane?

• Lever

• Wedge

• Screw

• Compound machine

What is the function of a lever?

• To oppose motion between surfaces.

• To move objects in the same direction as the applied force.

• To pivot or rotate about a point.

• To wrap around a cylinder or post.

What does a wheel and axle consist of?

• Two circular objects of the same size that rotate independently.

• Two circular objects of different sizes that are attached and rotate together.

• A grooved wheel with a rope wrapped around it.

• A circular object with spokes that connect to a central point.

What is a pulley?

• A circular object that rotates on a central axle.

• A wheel with teeth that meshes with a chain or belt.

• A grooved wheel with a rope or cable wrapped over it.

• Two circular objects of different sizes that rotate independently.

When force is used to move an object across a distance, this is called...

• effort

• power

• energy

• work

Tags

NGSS.MS-PS3-5

If the object does not move then what is happening

• nothing

• work

• power

• no work is being done on the object