Preskoči na glavni sadržaj

Sign up for FREE

Science 8-2: Mechanical Systems Section 2.0 Quiz

Posljednje ažuriranje 27 days ago

28

null

Using your notes, assigned work and videos answer the following mulitple choice questions.

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Obavezno

1

Pitanje 1

1.

Roads in the mountains have sections to help vehicles up a steep incline, by making sharp turns back and forth in opposite directions, after raising the vehicle a little higher in altitude. These roads are an example of a simple machine – the inclined plane, and are called ...

A reversals

B switchbacks

C zig zags

D turnabouts

Pitanje 2

2.

Your car has a flat tire, but you don’t have a jack to lift it up, so you can change the tire. What machine could you make that would make it possible to lift the car ...

A lever

B wedge

C pulley

D ramp

Pitanje 3

3.

Mechanical advantage is the amount by which a machine can multiply a force. The force that the machine applies to the object is called the ...

A input force

B output force

C force ratio

D Newton Force

Pitanje 4

4.

To calculate the mechanical advantage or force ratio, you divide the output force by the input force. A machine that is able to move an object that weighs 36 Newtons with 6 Newtons of force has a mechanical advantage of ...

A 6

B 30

C 36

D 42

Pitanje 5

5.

A pulley system can provide a mechanical advantage.
Look at the illustration and identify what the mechanical advantage of
this pulley system is.

A 2

B 3

C 4

D 5

Pitanje 6

6.

If it takes 45 N of force to lift a 180 N carton using a pulley system, what would the pulley system look like ...

A

null

B

null

C

null

D

null

Pitanje 7

7.

Speed Ratio is calculated by dividing the ...

A Output distance by the input distance

B Input distance by the output distance

C Output force by the input distance

D Input force by the output distance

Pitanje 8

8.

To calculate the speed ratio of a pulley system, you count...

A all the ropes

B only the ropes supporting the load

C only the ropes applying force

D all the ropes that are movebale

Pitanje 9

9.

In most machines, you don’t get something for nothing. When you gain a mechanical advantage, you are gaining ...

A force

B speed

C distance

D resistance

Pitanje 10

10.

A bicycle is a useful machine because it gets us from place to place much faster than we could walk. As a machine it has a mechanical advantage of less than one, but what about speed ratio? The speed ratio of a bicycle is ...

A 1

B more than 1

C less than 1

D cannot be determined

Pitanje 11

11.

What can account for the fact that mechanical advantage and speed ratio are different in real situations?

A improper calculations

B faulty equipment

C force of friction

D loss of energy

Pitanje 12

12.

Efficiency is a measure of how well a machine does work. Dividing the mechanical advantage by the speed ratio and multiplying the result by 100 will determine the efficiency of the machine. A pulley system that has a speed ratio of 3 and a mechanical advantage of
2 has an efficiency of...

A 33%

B 67%

C 60%

D 30%

Pitanje 13

13.

The scientific definition of work is ...
“Work is done when a force acts on an object to make the object move.”
Which statement below describes work being done.

A Hank worked very hard to get all his homework done.

B Doing math is hard work if you don’t like numbers.

C It was hard work for Sam to move the desk two meters.

D It was hard work trying to move the car, but it wouldn’t budge.

Pitanje 14

14.

Work is calculated using the formula W = F x d. If you lift a box onto your desk that is 0.4 meters off the floor, using 50 Newtons of force, how much work are you doing?

A 20 Joules

B 125 Joules

C 50.4 Joules

D 49.6 Joules

Pitanje 15

15.

In a car, what provides the force (energy source) that makes work (the car moving) possible?

A engine

B transmisson

C gasoline

D wheels

Pitanje 16

16.

Using a machine does not mean that less work is done. This is because ...

A Work input is never equal to work output

B Work input is equal to work output

C Less force means less distance

D More force means more distance

Pitanje 17

17.

When determining the efficiency of a certain machine, the students found that 1600J of work were needed to get 1200J of work from the machine. The efficiency of this machine was ...

A 2800 J

B 400 J

C 75%

D 25%

Pitanje 18

18.

A hydraulic system is able to move heavy loads because it uses this under pressure ...

A air

B water

C liquid

D nitrogen

Pitanje 19

19.

Hydraulic systems are used in many different applications. A hair stylist would use hydraulics in their shop to do this ...

A mix chemicals and dyes

B operate electric shears

C run the neon signs

D rasie and lower the chair

Pitanje 20

20.

Pressure is the measure of the force applied to a specific area. The unit of measurement is named after Blaise Pascal who worked with fluids. The unit of measure is the ...

A blaise

B pascal

C kilogram

D cubic meter

Pitanje 21

21.

Pascal’s Law states that pressure applied to an enclosed fluid is transmitted ...

A to the walls of the container which double the pressure

B equally in all directions throughout the fluid

C by the transfer force in the fluid

D to the opposite piston where it increases the force

Pitanje 22

22.

Pascal’s law enables these types of systems to work very effectively – hydraulics, which use a liquid and pneumatics, which use ...

A air

B oil

C water

D grease

Pitanje 23

23.

A common application of the hydraulic system is the
hydraulic jack, like the one shown here ...
The piston identified by # 1 is the ...

A syringe piston

B hoist piston

C output piston

D input piston

Pitanje 24

24.

The mechanical advantage in a hydraulic system is provided by the ...

A small psiton

B large piston

C flexible connection

D pressure in the fluid

Pitanje 25

25.

A good example of a hydraulic system at work inside the body is the ...

A Respiratory system

B Digestive system

C Circulatory system

D Excretory system

Pitanje 26

26.

The hydraulic jack, like the one shown here, identifies the input force piston and the output force piston ...
F_in = 50N
F_out = 1500N
The mechanical advantage of this hydraulic jack is ...

A 30

B 300

C 1000

D 2000

Pitanje 27

27.

If the area of the input piston, in the hydraulic lift shown in the question above, is 5cm², what would be the area of the output piston? Set up a ratio using this formula to solve for
A_large

A 10 cm²

B 30 cm²

C 150 cm²

D 300 cm²

Pitanje 28

28.

The disadvantage of the hydraulic system is similar to the disadvantage of levers and pulleys. To increase the force on the output piston, the input piston has to ...

A have less friction

B create more pressure

C move a greater distance

D be attached to the load