Science - Chapter 12 - Test 4/25/14

Question 1

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

Answer 1

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

Question 2

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

Answer 2

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

Question 3

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

Answer 3

1. the force you exert
2. the distance the object moves

Question 4

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

Answer 4

work = force x distance

Question 5

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

Answer 5

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

Question 6

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

Answer 6

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

Question 7

Force is measure in ______.

Answer 7

Force is measure in Newtons.

Question 8

Distance is measured in ______.

Answer 8

Distance is measured in meters.

Question 9

The SI unit of work is the _______.

Answer 9

The SI unit of work is the newton-meter.

Question 10

A newton-meter is also called a ______.

Answer 10

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

Question 11

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

Answer 11

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

Question 12

If the object does not move, ______ is done.

Answer 12

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

Question 13

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

Answer 13

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

Question 14

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

Answer 14

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

Question 15

Rolling or dragging a suitcase on the ground requires _____.

Answer 15

Rolling or dragging a suitcase on the ground requires work.

Question 16

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

Answer 16

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

Question 17

Name 3 closely related simple machines.

Answer 17

1. inclined plane
2. wedge
3. screw

Question 18

An inclined plane is a flat, _____ surface.

Answer 18

An inclined plane is a flat, sloped surface.

Question 19

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

Answer 19

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

Question 20

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

Answer 20

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

Question 21

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

Answer 21

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

Question 22

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

Answer 22

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

Question 23

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

Answer 23

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

Question 24

A _____ is an example of a wedge.

Answer 24

A zipper is an example of a wedge.

Question 25

________ holds the screw in place.

Answer 25

Friction holds the screw in place.

Question 26

How many classes of levers are there?

Answer 26

three

Question 27

Levers are classified according to the _______.

Answer 27

Levers are classified according to the location of the fulcrum.

Question 28

Lifting a heavy object is much easier with a _____.

Answer 28

Lifting a heavy object is much easier with a ramp.

Question 29

As the threads of the screw turn, they exert an _______ on the wood.

Answer 29

As the threads of the screw turn, they exert an output force on the wood.

Question 30

______-class levers change the direction of the input force.

Answer 30

First-class levers change the direction of the input force.

Question 31

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

Answer 31

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

Question 32

Name two simple machines that take advantage of turning.

Answer 32

1. pully
2. wheel & axle

Question 33

What are the 3 types of pulley systems?

Answer 33

1. fixed
2. movable
3. block & tackle

Question 34

A simple machine made of two connected objects that rotate about a common axis is called a ________.

Answer 34

A simple machine made of two connected objects that rotate about a common axis is called a wheel & axle.

Question 35

You use a pulley by pulling on one end of the rope, this is the _______ force.

Answer 35

You use a pulley by pulling on one end of the rope, this is the input force.

Question 36

The object in a wheel and axle with the larger radius is the ______.

Answer 36

The object in a wheel and axle with the larger radius is the wheel.

Question 37

What is an example of a wheel and axle?

Answer 37

paddle wheel on a boat

Question 38

Pulley systems are classified by the ______ of the wheels they contain.

Answer 38

Pulley systems are classified by the number and position of the wheels they contain.

Question 39

When you turn the wheel, the _______.

Answer 39

When you turn the wheel, the axle rotates.

Question 40

A _______ pulley is attached directly to the object you are attempting to move.

Answer 40

A movable pulley is attached directly to the object you are attempting to move.

Question 41

The machine exerts the _______ over the output distance.

Answer 41

The machine exerts the input force over the output distance.