ReviewUnit 6

8th Grade Integrated Science

1) Define work.

2) What unit is work measured in?

W = F x DJoules

1) Define power

2) What unit is power measured in?

P = W / TWatts

Solve

A construction worker pushes the wheelbarrow with the power of 50 J per 2 seconds how much power does he use?

3) Two cars have the same weight, but one of the cars

has an engine that provides twice the power of theother.

Which car can make it to the top of the North Ogden

Divide first? Explain.

Which car does more work to reach the top of thepass? Explain.

TEAM

4) Select three of the six simple machines

that you have learned about.

Provide at least three examples for eachmachine (9 total) of where you couldexpect to see those machines beingused.

1) Why was it important to “zero out” your scales before use?

1) What is the relationship between distance and weight for a balanced lever?

TEAM

Illustrate a 1st class, 2nd class, and a 3rd

class lever. Label the parts of the leversand then in words describe thedifferences between the three levers.

Under each illustration, provide at least 3examples of objects that could representthat lever.

TEAM

Based on your experiences in your labs withlevers, write one rule that could be appliedfor each different type of lever.

These rules should be focused on theeffort force and how it relates to moving theresistance force.

A simple machine is used to lift a weight. What

happens to the amount of force that must beexerted compared to doing the work without

amachine?

a. it increasesb. it decreasesc. it stays the samed. it can't be predicted

A simple machine is used to lift a weight. What happens

to the amount of work that must be done compared to

doing the work without a machine?

a. It increasesb. It decreasesc. It stays the samed. It depends on which simple machine is used 

Which one of the following simplemachines is a third class lever?a. Bumper jackb. Crowbarc. Fishing poled. Scissorse. Wheel barrow

If the blades of the scissors were lengthened,

what would happen to the amount of forceexerted at their tip?

a. It would not changeb. It would become greaterc. It would become lessd. It would be easier to cut tough materials 

What simple machines are found in the

wheelbarrow?a. inclined plane, leverb. lever, pulleyc. pulley, inclined planed. wheel, lever

Which of the following is an example of sliding

friction?a. A car going down the road.b. A person sanding a board.c. A ball being pushed across a table.d. A boy climbing a greased pole.e. A boulder being moved on rolling logs. 

 

1. What is the mechanical advantage of this inclined plane drawn above?a. 1.5b. 2c. 2.5d. 3

 

How could the mechanical advantage of

an inclined plane be increased?a. make the height tallerb. increase the weightc. decrease the weightd. make the plane longer

Explain how to find the ideal MA of alever.

What is a Mechanical Advantage?

Explain how you would find the MA of a

pulley system.

What are two functions that pulleys have?

Golf

1. Which would reduce the amount of force needed to lift the weight?

a. Ab. B and Cc. B and Dd. D 

 

Which would require you to pull therope the farthest?a. Ab. B and Cc. Cd. D

How many times easier to lift will "D" be

than "A"?a. the sameb. twice as easyc. three times easierd. four times easier