8. Simple machines

Question 1

When a machine is used to apply an input force, what is the measure of the amplification of the output force?

Answer 1

Mechanical advantage.

Question 2

What is a simple machine?

Answer 2

A basic mechanical device to transfer forces.

Question 3

What are the 6 types of simple machines?

Answer 3

Wheel and axle, inclined plane, wedge, lever, pulley, screw.

Question 4

What is a compound machine?

Answer 4

A machine made up of more than one simple machine.

Question 5

What is the mechanical advantage of a compound machine?

Answer 5

The product of the mechanical advantage of all the simple machines inside.

Question 6

Which has more efficiency - a simple or compound machine?

Answer 6

Simple.

Question 7

Why is a compound machine less efficient than a simple machine?

Answer 7

There are more points of friction in a compound machine.

Question 8

What is the total energy of a machine split into?

Answer 8

Useful energy and wasted energy.

Question 9

The efficiency of a machine is directly proportional and inversely proportional to what?

Answer 9

Output power and input power.

Question 10

Elizabeth pushes a box 12 meters up a ramp to load a truck that is 2 meters off the ground. What is the ideal mechanical advantage of the ramp?

Answer 10

6

Question 11

How does a ramp make work easier?

Answer 11

By giving you more output force than you input

Question 12

Curtis is building a model pyramid in his backyard. The final 500 kg block will have to be moved into a position 5.0 meters above the ground. Curtis can push the block on rollers up a ramp with a force of 1000 N. How long does he need to make the ramp?

Answer 12

24.5

Question 13

A 5-meter ramp lifts objects to a height of 0.75 meters. What is the mechanical advantage of the ramp?

Answer 13

6.7

Question 14

Joey’s little brother makes a ramp to push his toy dump truck up to his sandbox. If he uses 5 N of force to push the 12 N truck up the ramp, what is the mechanical advantage of his ramp?

Answer 14

2.4

Question 15

A ramp with a mechanical advantage of 4 is used to move a 38-newton load. What input force is needed to push the load up the ramp?

Answer 15

9.5

Question 16

Terrence wheels his wheelchair up a ramp using a force of 93 N. If the ramp has a mechanical advantage of 7, what is the output force?

Answer 16

651N

Question 17

A road sign through the Rocky Mountains says the road going up the side of a mountain pass at a 5% grade (i.e., there is a 5-meter gain in altitude for every 100 m of distance along the road). What is the mechanical advantage of the road?

Answer 17

20

Question 18

A ramp with a mechanical advantage of 13 lifts objects to a height of 11 meters. How long is the ramp?

Answer 18

143m

Question 19

When using a broom to sweep a floor, your mechanical advantage will be less than 1 and your fulcrum will be your hand at the top of the broom. This means the broom acts as which type of lever?

Answer 19

Class 3 Lever

Question 20

A standard bottle opener is an example of what type of lever?

Answer 20

Class 2 Lever

Question 21

A catapult is best described as what type of lever?

Answer 21

Class 1 Lever

Question 22

Jacob positions a class 1 lever so that the end he pushes down on is 0.5 m from the fulcrum. The object he is trying to lift is 0.1 m from the fulcrum. What is the IMA of the lever as he has it set up?

Answer 22

5

Question 23

Mr. D needs to create a lever with a mechanical advantage of 0.4. If he is going to apply his force 2 meters from the fulcrum, how far away must his load be from the fulcrum to get the correct mechanical advantage?

Answer 23

5 meters

Question 24

Elizabeth pushes a box 12 meters up a ramp to load a truck that is 2 meters off the ground. What is the ideal mechanical advantage of the ramp?

Answer 24

6

Question 25

Austin needs to lift a 300 N object using only 100 N of force. To accomplish this, he will need a simple machine with a mechanical advantage of what?

Answer 25

3

Question 26

What defines what a pulley system can do?

Answer 26

It can change the direction of the force and it can increase the output force.

Question 27

What does the pulley system shown below do to the force?

Answer 27

Only the direction of the force is changed.

Question 28

In the pulley system shown below, the force exerted on the machine is 30 N, and the force exerted on the load (the bucket) by the machine is 20 N. If the machine is moved by a distance of 20 cm, by what distance does the load (the bucket) move?

Answer 28

30cm

Question 29

What behaves most like a first-class lever, with the fulcrum between the force and the load?

Answer 29

Single, fixed pulley system

Question 30

In the pulley system shown below, the force exerted on the machine and on the load by the machine are equal. Which of the following correctly represents the ideal mechanical advantage (IMA) of the pulley system?

Answer 30

1, because only the direction of the input force is changed.

Question 31

Given the diagram shown below, if the rope is pulled with an input force of 10 N, what would be the output force?

Answer 31

20 N

Question 32

The system shown below consists of which of the following?

Answer 32

A movable and a fixed pulley

Question 33

Which of the following statements correctly describes the pulley system shown below? * It has an IMA of 1, because it only changes the direction of the force. * It has an IMA of 2, because there are only two support ropes. * It has an IMA of 3, because there are three support ropes.

Answer 33

It has an IMA of 3, because there are three support ropes.

Question 34

The pulley system shown below involves an input force lifting 240 N of load a distance of 10 cm. Given that the machine is moved a distance of 30 cm, what is the input force?

Answer 34

Question 35

Explain why the ideal mechanical advantage of a single fixed pulley system is 1.

Answer 35

This is because, in this system, only one segment of rope pulls up the load, resulting in an ideal mechanical advantage of 1. The ideal mechanical advantage equals the number of rope segments pulling up the object.