Chapter 4 Section 1 Flashcards

1
Q

Machines make doing work easier or faster by changing the _____ needed to do the work

A

force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Work is a _____ applied through a _____
or
the _____ transferred when a _____ makes an object _____

A

force
distance
energy
force
move

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the formula for work

A

W = F x d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the unit used to measure work?

A

joules ( J )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

For you or a force to do work, 3 conditions must be met:

A
  1. you have to be physically touching the object
  2. the object must move
  3. the movement of the object must be in direction of the force
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What always occurs when work is done?

A

a transfer of energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When you do work on an object, you increase the objects _______ because _______

A

energy
you gave the object your own energy (Transfer)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

When are you doing work on an object?

A

when you are physically touching the object applying force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what happens if the object keeps moving after you apply force

A

you are no longer doing work on the object because you are no longer touching the object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

When the force and motion of the object are ______ the maximum amount of work is being done

A

parallel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

When the force and motion of the object are ______ then no work is being done

A

perpendicular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

when the force and motion of the object are ______ less than maximum (partial) work is being done

A

at an angle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

a machine is a device that _____ or _____

A

changes the force
increases the motion from work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

A simple machine is a machine that does _____ with only _____

A

work
one movement of the machine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the six simple machines

A

lever
pulley
wheel and axel
inclined plane
wedge
screw

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the modified levers and inclined planes

A

levers: pulley, wheel and axel
inclined planes: wedge, screw

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

A compound machine is a combination of _____

A

two or more simple machine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Efficiency is the ratio of _____ to _____

A

output work to input work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

No machine can increase both _____ and _____ at the same time

A

force
speed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

You always put more _____ into a machine than you get out of that machine

A

work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

No machine is 100% efficient because of _____

A

friction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is the formula for efficiency

A

EFF = Wout/Win x 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

An _____ is a theoretical machine in which the amount of work put into the machine (Win) is equal to the amount of work you get out of the machine (Wout)

A

ideal machine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Why do ideal machines not exist

A

friction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Machines _____ the speed of getting work done
increase
26
Machines multiply/increase _____
force
27
Machines change the _____ of the force
direction
28
Do machines always multiply/increase force
no
29
We can describe the effectiveness of a machine by increasing _____ by its mechanical advantage
force
30
Input force is the force that...
a person or device such as a motor applies to the machine
31
Output force is the force that...
the machine applies to another object
32
What is the formula for mechanical advantage
MA = Fout/Fin
33
If mechanical advantage is less than 1 then input force is ______ and the machine is _____ at making work easier
greater than the output force not good
34
If mechanicla advantage is greater than 1 the machines output force is _____. So...
greater than the input force this would be a better machine at making work easier
35
Most simple machines make work easier by what is called a _____
Force-DIstance tradeoff
36
Force-DIstance tradeoff is when you _____ on the machine/object for a ______ to do the work needed. The force you put on the machine/object is ______ but ______
apply a force longer distance multiplied by the machine only moves a small distance
37
A lever is a _____ that is free to pivot or turn around a ______
bar fixed point
38
The fixed point the lever pivots on is the _____
fulcrum
39
Input arm of a lever is the distance from _____
the fulcrum to the point the input force is applied
40
Output arm is the distance from ______
the fulcrum to the output force
41
What is the IMA formula for a lever
IMA = Lin/Lout
42
The difference between the 3 classes of levers is the _____
location of the fulcrum, the input force, and the output force
43
In a first class lever the _____ is located in the middle
fulcrum
44
In a second class lever the _____ is located in the middle
output
45
In a third class lever the _____ is located in the middle
input
46
In a first class lever the output force is always...
in the opposite direction to the input force
47
What is an example of a first class lever?
seesaw
48
In a second class lever, the output force is always...
greater than the input force
49
What is an example of a second class lever?
wheelbarrel
50
In a third class lever the output force is always...
less than the input force
51
What is an example of a third class lever?
broom anything you swing (bat, golf club)
52
What type of lever is a car door
2nd
53
What were the first discovered simple machines
lever pulley screw
54
what was the last discovered simple machine
inclined plane
55
Who said "With a big enough lever and a place to rest it, a person could move the world"
Archimedes
56
A pulley is a ______ with a rope, cable, or chain running along the groove that is used to ______
grooved wheel lift objects
57
A fixed pulley changes ______ of input force but does not _____ input force
direction increase
58
A fixed pulley is a ______ lever
modified first class
59
Movable pulleys ______ input force
increase
60
A pulley in which one end of the rope is fixed and the wheel can move is what kind of pulley
movable pulley
61
A pulley that is attached to something that does not move is what kind of pulley
fixed pulley
62
A system of pulleys consisting of fixed and movable pulleys is what kind of pulley
block and tackle
63
What is the IMA of a fixed pulley
1
64
What is the IMA of a movable pulley
2
65
What is the IMA of a block and tackle
the number of rope segments supporting the weight
66
What is the IMA formula for a wheel and axel
IMA = rw/ra
67
a wheel and tackle is a simple machine consisting of a _____ attached to the _____ of a larger wheel so that the wheel and axle rotate together
shaft or axle center
68
What is the fin and fout of a wheel and axle
fin: wheel fout: axle
69
What is an example of a wheel and axle
door knob steering wheel
70
What is the IMA formula for an inclined plane
IMA = l/h ( length of slope/height of slope)
71
An inclined plane is a sloping surface that _____ required to _____
reduces the amount of force do work
72
What is an example of an inclined plane
wheelchair ramp bike ramp
73
A screw is a ______ wrapped in a _____ around a cylindrical post
an inclined plane spiral
74
What makes the IMA of a screw larger
when the threads are closer together
75
What are examples of a screw
screw, umbrella drill thing
76
What is the IMA formula for a wedge
IMA = l/w
77
A wedge is an ______ with 2 _____ sides
inclined plane sloping
78
A wedge changes _____ of the input force
the direction
79
What is an example of a wedge
blade of knife, head of axe, end of scissors
80
why do we use machines
to make work easier
81
How do you make work easier
force-distance tradeoff
82
What do simple machines do
increase your force change direction of your force
83
Machines make work easier or ______ by changing the ______ needed to do work
faster force
84
Can machines increase the amount of work done
no
85
Fout can also be callled
load
86
Fin can also be called
effort
87
Can a machine increase your input force
yes
88
What are the 2 reasons why a machine is not 100% effective
friction Any time energy changes forms efficiency is lost
89
What are the three ways machines are useful
changes direction of force increases force makes work faster