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Choose the best answer.

The fact that the force times the distance on one side of a lever's fulcrum equals the force times the distance on the other side of the fulcrum, is represented in the _____.

Law of Motion

Law of Conservation of Energy

Law of Moments

Law of Conservation of Mass
2.
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If the sum of all forces in a system are equal to zero, then the system is in _____.

incomplete balance

transit

movement

equilibrium
3.
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Mechanical energy is sent through a device called a(n) _____ that can perform work.

fulcrum

resistance

machine

torque
4.
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Which one contains both an inclined plane and a wheel and axle?

none have both

chisel

screw

ramp
5.
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A machine that has a bar and a fulcrum is a(n) _____.

pulley

lever

inclined plane

screw
6.
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Another name for the fulcrum is _____.

lever

pivot point

effort arm

resistance arm
7.
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​​​(Double points) A water well has a wheel with a radius of 50 cm and an axle with a radius of 10 cm that is attached to a bucket that brings up the water from the well. What Mechanical Advantage does the wheel and axle machine provide?

0.2

3.4

5

1
8.
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Two forces are at work in a lever; they are the resistance force and the _____ force.

vector

effort

torque

projectile
9.
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This formula represents _____.

Law of Conservation of Energy

Law of Motion

Law of Moments

Law of Conservation of Mass
10.
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A rope arranged over several wheels is connected to a load that needs to be lifted with less force than if it was done directly. The machine used is a(n) _____.

inclined plane system

pulley systems

lever system

wheel and axle system
11.
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When the the torques in system equal zero, the system is in _____ equilibrium.

universal

major

translational

rotational
12.
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A lever with the fulcrum between the effort arm and the resistance arm is a _____.

type 2 lever

type 3 lever

type 1 lever

torque
13.
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Workers building pyramids in ancient Egypt needed to move a very heavy stone out of the way of a ramp they were constructing. The best machine they could use to do this work was a _____.

torque

type 2 lever

type 3 lever

type 1 lever
14.
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​​​(Double points)The distance to the fulcrum from the effort force is 6.1 m and the force is 34 N. The distance from the fulcrum to the resistance force is 8.7 m.
What is the value of
assuming the load is balanced?

5.3 N

67 N

23.8 N

15 N
15.
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Which one contains a lever?

inclined plane

ramp

chisel

pliers
16.
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A lever's Mechanical Advantage can be calculated by _____.

length resistance arm /length resistance and effort arm

length effort and resistance arm /length resistance arm

length effort and resistance arm /length effort arm

length of effort arm/length of resistance arm
17.
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You have several pulleys supporting a load of 15 kg, to calculate the effort you use _____.

15 kg multiplied by number of pulleys

15 kg divided by number of pulleys

15 kg divided by number of ropes supporting the load

15 kg multiplied by number of ropes supporting the load
18.
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You tour a shipyard and notice dockworkers offloading pallets by means of a pulley system. The supervisor tells you that he and fellow workers only had to exert 150 N effort to offload the pallets totaling 900 N. How many pulleys were they using?

3

4

1

6
19.
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​​​(Double points) A machine has useful work output of 85 J, whereas its total work was 115 J. What is the machine's efficiency?

20.
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A device used to pull a bucket out of a well is made with rope tied a cylinder. A crank handle with a length greater the radius of the cylinder is attached. This type of machine is called a(n) _____.

wheel and axle system

lever system

pulley systems

inclined plane system
21.
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M.A. = _____ length/height

big

object

slant

small
22.
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A(n) _____ is the axis on which a bar can pivot; also called the point of rotation.

resistance arm

fulcrum

effort arm

lever
23.
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​​​(Double points) A pulley system is in equilibrium. It supports a load of 252 pounds with a force of 28 pounds. What is the pulley system's M.A.?

3

2

10

9
24.
Choose the best answer.

The reason to use machines to help accomplish work is the _____.

inertia

torque

mechanical advantage

lift
25.
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The formula for efficiency is _____.

26.
Choose the best answer.

An object is not moving because no forces are acting on it, this is an example of _____ equilibrium.

motion

universal

constant

translational

1 answer

Here are the best answers to each of the questions:

  1. Law of Moments
  2. equilibrium
  3. machine
  4. screw
  5. lever
  6. pivot point
  7. 5
  8. effort
  9. Law of Moments
  10. pulley systems
  11. rotational
  12. type 1 lever
  13. type 2 lever
  14. 23.8 N
  15. pliers
  16. length of effort arm/length of resistance arm
  17. 15 kg divided by number of ropes supporting the load
  18. 6
  19. Efficiency = (Useful Work Output / Total Work Input) x 100; therefore, Efficiency = (85/115) x 100 = 73.91%
  20. wheel and axle system
  21. small
  22. fulcrum
  23. 9
  24. mechanical advantage
  25. Efficiency = (Useful Work Output / Total Work Input) x 100
  26. translational

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