MA, SR, & Efficiency Practice Problems Flashcards

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1
Q

The Mechanical advantage of a bike is 0.4 and the speed ratio is 10. What is the Efficiency?

A

0.4/10 x100=4%

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2
Q

The speed ratio is 50, the mechanical advantage is 20. Calculate the efficiency.

A

20/50 x100=40%

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3
Q

Calculate the mechanical advantage. A person is pushing someone on a swing, they exert 50N and the swing hits someone at 100N sending the person flying.

A

100N/50N=2

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4
Q

Calculate the mechanical advantage when it takes 200N to move a 550N object.

A

550N / 200N=2.75

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5
Q

If a machine requires 17N of work put into it to exert 40N, what is the mechanical advantage of this machine?

A

40N / 17N=2.35

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6
Q

A machine produced 121N of force when 100N is input. What is the mechanical advantage of this machine?

A

121N / 100N=1.21

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7
Q

A company is developing a machine, currently the Mechanical advantage is 5.6 and the Speed ratio is 6. In order for the machine to qualify as “Worth” it must have an efficiency of 78%. Is this machine “Worth it?”

A

MA/SR x 100=efficiency

5.6/6x100=93%

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8
Q

You push a bike pedal 10cm and the bike moves 100cm. Calculate the Speed ratio.

A

SR= I/O

SR=10/100=0.1

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9
Q

Freddie had a machine lift 340N while he only lifted 170N. What is the mechanical advantage of this machine?

A

340N / 170N=2

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10
Q

Hank invented a machine that could move 400N with only 130N input. What is the mechanical advantage of this machine?

A

400N / 130N=3.08

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11
Q

Arnold built a machine to help deliver the morning paper. He had to pull with 38N of force to move a stack of papers that had a force of 92N. What is the mechanical advantage of this machine?

A

92N / 38N=2.42

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12
Q

Arnold also used his machine to move 30N of recycled pop cans, but he must input 8N of force to do this. What is the mechanical advantage of this machine?

A

30N / 8N=3.75

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13
Q

Sam’s newest invention takes 2N and converts it into 4N of force. What is the MA?

A

4N / 2N=2

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14
Q

This mechanical device has an input distance of 45m and an output distance of 15m. Calculate the speed ratio.

A

45m / 15m=3

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15
Q

Hans’s tree branch trimming machine needs to be moved 0.5m to cut a distance of 0.2m. Calculate the speed ratio.

A

0.5m / 0.2m=2.5

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16
Q

Robert’s machine moves 2.3m when the input force moves 5m. Calculate the speed ratio.

A

5m / 2.3m=2.17

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17
Q

This mechanical device moves 3.6m of each 8.5m of input force. Calculate the speed ratio.

A

8.5m / 3.6m=2.36

18
Q

The input distance is 52m and the output distance is 42m. Calculate the speed ratio.

A

52m / 42m=1.23

19
Q

Freddie’s machines input distance is 25m while the load moves 11m. Calculate the speed ratio.

A

25m / 11m=2.27

20
Q

Hank’s machine only moves the load 24m when the input force moves 75m. Calculate the speed ratio.

A

75m / 24m=3.125

21
Q

Arnold’s machine moves the load 1.8m when the input distance is 6.2m. Calculate the speed ratio.

A

6.2m / 1.8m=3.44

22
Q

Arnold’s second machine has an input distance of 10m to an output distance of 2m. Calculate the speed ratio.

A

10m / 2m=5

23
Q

The load moves 0.12m when the effort force moves 0.25m. Calculate the speed ratio.

A

0.25m / 0.12m=2.08

24
Q

Mr. foisy used a broomstick to smack Keyton. The broomstick hit Keyton in the face with a MA of 2 but the SR was 4. What was the efficiency of the device?

A

E=50%

25
Q

The Omnikin ball applied 100N to Owen’s face, but the input was 4N from Mr. Foisy. What was the mechanical advantage?

A

100N/4N=25

26
Q

Jacob lifted a car with 156n of force when 123n is input into a lever. What is the MA of the lever?

A

156N/123N=1.26

27
Q

Lee used 15N to carry a computer across the room on a cart. After his initial effort the output force created an astounding mechanical advantage of 8. What was the output force?

A

O=MA x I

O=8 x 15N = 120N

28
Q

Olivia was making a Rube Goldberg Machine and used 8N to knock down some dominoes. The dominoes transferred 40N of force amongst each other. In addition, the input distance to the first domino was 4cm and the overall output distance was 2cm. What is the efficiency of the system?

A

MA=O/I=40N/8N=5

SR=I/O=4/2=2

Eff=MA/SR x100

Eff=5/2 x100=250%

29
Q

Corny slammed down a basketball with 30N of force. The basketball travelled downwards 75cm and bounced upwards 150cm. What is the speed ratio?

A

SR=I/O

SR=75/150

SR=0.5

30
Q

The big bad wolf blows onto the straw house with an MA of 3. If the output of the collapsed building is 250N, what is the input force by the big bad wolf?

A

I = O/MA

I=250N/3

O=83.333N

31
Q

The apple-pen dude shoves a pen through an apple with 576N. It comes out the other side with 606N. What is the Mechanical Advantage of the wedge?

A

MA=O/I

MA=606N/576N

MA=1.05

32
Q

Keyton gets mad at a computer game and throws his computer across the room at (over) 9000N. It hits the wall with 9001N. What is the Mechanical Advantage?

A

MA=O/I

MA=9001/9000

MA=1.00

33
Q

Elena invented a machine to turn off her alarm clock. Her machine used 2.4 N and had a MA of 5. What is the output force?

A

O=MAxI

O=2.4N x 5

O=12N

34
Q

Danika created a pulley. Her machine had a MA of 2 and produced 3.5 N. What is input force?

A

I=O/MA
I=3.5N/2

I=1.75N

35
Q

Hunter invented a machine to make toast. His machine used 3.6 N and produced 8.4 N. What is the mechanical advantage?

A

MA=O/I

MA=8.4N/3.6N

MA=2.33

36
Q

Keyton smashes his face on the wall and requires stitches. His skin reformed and stretched away from the wound. The doctor needs to apply 2000 Newton’s but is using a vice clamp on Keyton’s head. There for he only needs 725 Newton’s to seal the wound. What is the MA of the clamp?

A

MA=2.75

37
Q

Jacob needed to move a bunch wolf drawings up a small inclined plane and into the local drawing store. The ramp had a height of 2m, and a length of 20m which Jacob must push his drawings across. What is the speed ratio of the ramp?

A

SR=I/O

SR=20m/2m

SR=10

38
Q

Kahlan needed to rip apart her small orange, so she built a small machine that would rip it apart. The small machine produced 7483n when the input was 478n. What is the mechanical advantage?

A

MA=O/I

MA=7483N/478N

MA=15.6

39
Q

Reece had to lift a few tables and Corny was sitting on the tables resulting in an output of 190N. If the MA is 0.5 how much force would Reece input?

A

I=O/MA

I=190N/0.5

I=380N

40
Q

Liam kicked the soccer ball at the goal moving his leg a distance of 80cm. The ball travelled 900cm. What is the speed ratio?

A

SR=I/O

SR=80cm/900cm

SR=0.08