Science - Chapter 12 - Test 4/25/14 Flashcards

1
Q

To do work on an object, the object must move some ______ as a result of your work.

A

To do work on an object, the object must move some distance as a result of your work.

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2
Q

Work is done on an object when the object moves in the same direction in which the _____ is exerted.

A

Work is done on an object when the object moves in the same direction in which the force is exerted

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3
Q

The amount of work you do depends on what two things?

A
  1. the force you exert
  2. the distance the object moves
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4
Q

The amount of work done on an object can be determined by using what formula?

A

work = force x distance

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5
Q

Name 3 factors that can be changed by a machine to make work easier.

A
  1. amount of force you exert
  2. distance over which you exert the force
  3. direction in which you exert
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6
Q

When you do work, the force you exert is called ______.

A

When you do work, the force you exert is called input force.

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7
Q

Force is measure in ______.

A

Force is measure in Newtons.

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8
Q

Distance is measured in ______.

A

Distance is measured in meters.

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9
Q

The SI unit of work is the _______.

A

The SI unit of work is the newton-meter.

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10
Q

A newton-meter is also called a ______.

A

A newton-meter is also called a Joule (J).

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11
Q

Machines do not reduce the amount of work that you do, they _____ the way you do work.

A

Machines do not reduce the amount of work that you do, they change the way you do work.

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12
Q

If the object does not move, ______ is done.

A

If the object does not move, no work is done.

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13
Q

You do _____ any time you exert a force on an object that causes the object to move some distance.

A

You do work any time you exert a force on an object that causes the object to move some distance.

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14
Q

When you lift an object, the upward force you exert must be at least _____ to the object’s weight.

A

When you lift an object, the upward force you exert must be at least equal to the object’s weight.

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15
Q

Rolling or dragging a suitcase on the ground requires _____.

A

Rolling or dragging a suitcase on the ground requires work.

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16
Q

A ______ is the most basic device for making work easier.

A

A simple machine is the most basic device for making work easier.

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17
Q

Name 3 closely related simple machines.

A
  1. inclined plane
  2. wedge
  3. screw
18
Q

An inclined plane is a flat, _____ surface.

A

An inclined plane is a flat, sloped surface.

19
Q

A _____ can be though of as an inclined plane wrapped around a cylinder.

A

A screw can be though of as an inclined plane wrapped around a cylinder.

20
Q

The fixed point that a lever pivots around is called the _____.

A

The fixed point that a lever pivots around is called the fulcrum.

21
Q

An inclined plane allows you to exert your ______ over a longer distance

A

An inclined plane allows you to exert your input force over a longer distance

22
Q

A ramp is an example of a simple machine called an ________.

A

A ramp is an example of a simple machine called an inclined plane.

23
Q

A _____ is a device that is thick at one end and tapers to a thin edge at the other end.

A

A wedge is a device that is thick at one end and tapers to a thin edge at the other end.

24
Q

A _____ is an example of a wedge.

A

A zipper is an example of a wedge.

25
\_\_\_\_\_\_\_\_ holds the screw in place.
***_Friction_*** holds the screw in place.
26
How many classes of levers are there?
three
27
Levers are classified according to the \_\_\_\_\_\_\_.
Levers are classified according to the ***_location of the fulcrum_***.
28
Lifting a heavy object is much easier with a \_\_\_\_\_.
Lifting a heavy object is much easier with a ***_ramp_***.
29
As the threads of the screw turn, they exert an _______ on the wood.
As the threads of the screw turn, they exert an ***_output force_*** on the wood.
30
\_\_\_\_\_\_-class levers change the direction of the input force.
***_First_***-class levers change the direction of the input force.
31
A _________ is the most basic device for making work easier.
A ***_simple machine_*** is the most basic device for making work easier.
32
Name two simple machines that take advantage of turning.
1. pully 2. wheel & axle
33
What are the 3 types of pulley systems?
1. fixed 2. movable 3. block & tackle
34
A simple machine made of two connected objects that rotate about a common axis is called a \_\_\_\_\_\_\_\_.
A simple machine made of two connected objects that rotate about a common axis is called a ***_wheel & axle_***.
35
You use a pulley by pulling on one end of the rope, this is the _______ force.
You use a pulley by pulling on one end of the rope, this is the ***_input_*** force.
36
The object in a wheel and axle with the larger radius is the \_\_\_\_\_\_.
The object in a wheel and axle with the larger radius is the ***_wheel_***.
37
What is an example of a wheel and axle?
paddle wheel on a boat
38
Pulley systems are classified by the ______ of the wheels they contain.
Pulley systems are classified by the ***_number and position_*** of the wheels they contain.
39
When you turn the wheel, the \_\_\_\_\_\_\_.
When you turn the wheel, the ***_axle rotates_***.
40
A _______ pulley is attached directly to the object you are attempting to move.
A ***_movable_*** pulley is attached directly to the object you are attempting to move.
41
The machine exerts the _______ over the output distance.
The machine exerts the ***_input force_*** over the output distance.