Work and Machines Quiz

__ is a measure of how much of the work put into a machine is changed to useful work put out by the machine.

What is the purpose of a machine?

• increase your speed

• make it easier to do the job

• increase your efficiency

• all of these

If the work is constant and the distance is decreased, how will the force be affected?

• It decreases.

• It increases.

• It remains the same.

• none of these

A boy holding heavy bags begins to walk forward. Is work being done by his arms?

What is a device that does work with only one movement and changes the size or direction of a force?

• compound machine

• effort machine

• screw

• simple machine

What is a lever with a mechanical advantage greater than 1 is used to do?

• change direction

• increase distance

• increase force

• increase distance and change direction

Machines make tasks easier by changing either the magnitude or the direction of what?

• force

• work

• energy

• velocity

Tags

NGSS.MS-PS2-1

When a machine is used to perform a task, work output is always __ than work input.

To calculate mechanical advantage, you divide the __ force by the input force.

How much total work do you do when you lift a 50 kg microwave 1.0 m off the ground and then push it 1.0 m across a counter with a force of 50 N?

• 300 J
• 540 J

• 450 J
• 600 J

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5