Study Island
Copyright © 2013 Edmentum - All rights reserved.
Generation Date: 10/25/2013
Generated By: Brett LaGrange
1. Select the choice that best completes the following sentence.
Simple machines
B. / reduce the amount of energy needed to do work.
C. / are tools that make work easier.
D. / cannot be combined to make compound machines.
2. Adam uses a fixed pulley, such as the one shown below, to lift an object.
Adam applies an input force to the pulley as he pulls down to lift the object. As he does this, Adam wonders about how the pulley is helping him. How is the pulley helping Adam lift the object?
A. / All of these answers are correct.B. / A fixed pulley increases the distance over which the force is applied.
C. / A fixed pulley helps Adam change the direction of the effort force.
D. / A fixed pulley lowers the amount of force needed to do the same amount of work.
3. The efficiency of a system is determined by
A. / dividing the work output of the system by the work put into the system.B. / adding the work output of the system to the work put into the system.
C. / multiplying the work output of the system by the work put into the system.
D. / subtracting the work output of the system from the work put into the system.
4. Jeffrey is using a pulley to get water from a well. He loops a rope over the top of a pulley wheel, then ties the rope to a bucket. He lowers the bucket into the water. To bring the bucket and water up from the well, Jeffrey pulls down on his end of the rope.
Why does Jeffrey apply a pulling force to the rope?
B. / because adding his force to the force generated by the pulley will get the job done faster
C. / to signal to the pulley to start drawing water from the well
D. / to test the tension in the rope before he uses it to climb down into the well
5. The toy crane below is a compound machine.
Which of the following statements about compound machines is true?
B. / Only compound machines can have a mechanical advantage of 2 or greater.
C. / Only compound machines can change the size or direction of a force.
D. / Compound machines consist of two or more simple machines working together.
6. Which simple machine can be described as a rope that is threaded through a wheel or disk?
A. / leverB. / screw
C. / inclined plane
D. / pulley
7. Rubia was given a type of inclined plane called a ramp in her science class. Her teacher told her that the ramp should have a mechanical advantage of 3.
Rubia pulled a block up the ramp, but afterward she calculated that the mechanical advantage of the ramp was 2.8 instead of 3. Her teacher said she did not make a mistake. What did Rubia calculate?
B. / the ideal operating power of the ramp
C. / the ideal mechanical advantage of the ramp
D. / the actual mechanical advantage of the ramp
8.
In the drawing above, what type of simple machine is shown in red?
A. / leverB. / screw
C. / pulley
D. / inclined plane
9. The mechanical advantage of a simple machine
A. / creates a force without the input of work.B. / increases the amount of force needed for work.
C. / allows work to be done without an input force.
D. / reduces the amount of force needed for work.
10. Which of the following is an example of work being done on an object?
A. / Water in a pot changes into steam.B. / A man pushes a couch across the room.
C. / A box rests on the floor.
D. / A prism scatters ultraviolet light into visible light.
11. When using scissors to cut paper, which two types of simple machines are being used?
A. / wheel and axle and inclined planeB. / lever and inclined plane
C. / pulley and lever
D. / lever and wheel and axle
12. What is mechanical advantage?
A. / a property of some machines that allows them to do work with no input forceB. / a measure of how much a machine multiplies the force applied to it
C. / a characteristic that compound machines have and simple machines lack
D. / a theory stating that machines are better at performing tasks than humans
13. Energy enables an object to do work.
Work is done when
B. / no force is put on an object, but the object moves at varying speeds in a random direction.
C. / no force is put on an object, and the object does not move in any direction.
D. / a force is put on an object, but the object does not move in any direction.
14. Which simple machine can be described as a shaft that is attached to the center of a wheel?
A. / pulleyB. / inclined plane
C. / lever
D. / wheel and axle
15. Which of the following pictures shows a person using a compound machine?
W. /X.
Y. /
Z.
A. / W
B. / X
C. / Z
D. / Y
16. A lumberjack is chopping wood with an ax. How does the ax make the lumberjack's job easier?
A. / The ax multiplies the amount of force that is applied to the wood.B. / The ax reacts with the wood so that it can be split more easily.
C. / The ax multiplies the amount of work that is applied by the lumberjack.
D. / The ax is heavy so it can split wood more easily.
17. The______of a machine is the amount by which a machine would multiply the force applied to it if no energy were lost due to friction.
A. / ideal operating powerB. / actual operating power
C. / ideal mechanical advantage
D. / actual mechanical advantage
18. Effort force applied to a wheel is______when it is transferred to the axle because the axle travels a______distance than the wheel.
A. / multiplied, shorterB. / multiplied, longer
C. / divided, longer
D. / divided, shorter
19. Which of the following is an example of work being done on an object?
A. / A wagon is used to carry vegetables from a garden.B. / A pulley is used to get water from a well.
C. / A hammer is used to remove a nail from a wall.
D. / all of these
20. The diagram below shows an inclined plane (in red) that movers use to raise heavy objects against the force of gravity and into a truck.
Which of the following is true about the simple machine shown in red?
B. / It shortens the distance needed to carry objects into the truck.
C. / It reduces the amount of energy needed to carry objects into the truck.
D. / It reduces the weight of objects being carried into the truck.
21.
Lifting up a paint can lid with a screwdriver is an example of using a______.
A. / wheel and axleB. / block and tackle
C. / pulley
D. / lever
22. Look at the diagram of the wheel and axle below.
The larger the radius of a wheel in comparison to the radius of its axle, the______the mechanical advantage will be.
B. / greater
C. / less stable
D. / more stable
23.
Which of the following correctly explains why one of the above levers can lift the object with less effort force?
B. / Lever Y is a third-class lever and will require less effort force than lever X, which is a second-class lever.
C. / Lever X is a third-class lever and will require less effort force than lever Y, which is a second-class lever.
D. / Lever Y will require less effort force because its fulcrum is closer to the input force than lever X's fulcrum.
24. A doorknob is an example of a______. It changes the______of the input force.
A. / wheel and axle; directionB. / pulley; size
C. / pulley; direction
D. / wheel and axle; size
25.
In the diagram above, a heavy box is being lifted. What is the function of the pulley in this situation?
A. / to decrease the height that the box will be raisedB. / to change the direction of the input force
C. / to increase the distance over which the input force is applied
D. / to reduce the amount of input force needed
26. Andy's teacher asked him to come up to the front of the class to demonstrate work. Which of the following could Andy do in the classroom to demonstrate work?
A. / Andy sits in his chair, doing nothing.B. / Andy holds a book.
C. / Andy pushes against a desk, and it doesn't move.
D. / Andy pushes a desk across the floor.
27. Which of the following is defined as the ratio of the energy delivered by a system to the energy supplied for its operation?
A. / powerB. / work
C. / efficiency
D. / mechanics
28. Look at the diagram of the wheel and axle below.
The mechanical advantage of a wheel and axle is found by
B. / dividing the radius of the wheel (R) by the radius of the axle (r)
C. / multiplying the radius of the wheel (R) by the radius of the axle (r)
D. / subtractingtheradiusoftheaxle(r)fromtheradiusofthewheel(R)
29. A wheel and axle is a type of simple machine that consists of a large object (the wheel) that surrounds and turns a smaller object (the axle).
Which of the following is an example of a wheel and axle?
B. / steering wheel
C. / screwdriver
D. / all of these
30. The simple machine marked with an arrow below is a straight, slanted surface that helps elevate a load.
What is this device called?
B. / a pulley
C. / a lever
D. / an inclined plane