Work and Simple Machines Quiz

What is the scientific definition of work?

• Using a force to change the direction of an object

• Using a force to lift an object

• Using a force to stop an object from moving

• Using a force to move an object a distance

According to the scientific definition, which of the following is considered work?

• A teacher lecturing to her class

• A mouse pushing a piece of cheese with its nose across the floor

• A scientist delivering a speech to an audience of his peers

• A woman carrying a 20 kg grocery bag to her car

What is the formula for calculating work?

• Work = Force x Distance

• Work = Mass x Acceleration

• Work = Speed x Time

• Work = Power x Time

Which of the following is an example of a second-class lever?

• Nut crackers

• Wheelbarrows

• Hammers

• Tweezers

What is the mechanical advantage of a fixed pulley?

• 4

• 3

• 1

• 2

In which simple machine is friction both an advantage and a disadvantage?

• Pulley

• Wedge

• Wheel and Axle

• Lever

Why is it not possible to have a machine with 100% efficiency?

• Efficiency is not important in machines

• Machines are not designed to be 100% efficient

• 100% efficiency is impossible to achieve

• Friction reduces efficiency

What is the relationship between effort force, effort distance, and work input?

• Effort force and effort distance are directly proportional to work input

• Effort force and effort distance are inversely proportional to work input

• Effort distance and work input are directly proportional to effort force

• Effort force and work input are directly proportional to effort distance

What is the mechanical advantage of an inclined plane?

• Equal to the length of the slope divided by the height of the inclined plane

• Equal to the height of the inclined plane divided by the length of the slope

• Equal to the input force divided by the output force

• Equal to the output force divided by the input force

What is the purpose of a pulley?

• To increase the distance or speed of a force

• To change the direction of a force

• To increase the magnitude of a force

• All of the above