Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physics Practical > Definitions > Flashcards

Definitions Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

Error

A

The difference between the measured value and the true value

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

Uncertainty

A

The range/interval within which the true value lies

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

Independent variable

A

The variable for which values are changed by the experimenter

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

Dependent variable

A

The variable for which values are measured for each and every change of the independent variable

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

Control variable

A

May affect the outcome of the investigation

Must be kept constant or at least monitored

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Random error

A

Present due to the way an instrument works, the surrounding environment changing or the way it is used

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

How is random error reduced

A

By taking repeated values and then averaging them

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

Systematic errors

A

Measurements that are consistently too large or too small by the same amount each time

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

Why might we have systematic errors

A

Not measuring zero error
Not calibrating equipment
Poor technique ( causing parallax error)
Recording the wrong unit

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

What is zero error

A

When the measuring equipment is not set on zero accurately

Should be added or subtracted from recorded values

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

How to take zero error into consideration

A

Minus or add onto recorded values

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

How can systematic error be seen on a graph

A

The line of best fit doesn’t go through zero

Doesn’t effect gradient of line of best fit but simply alters y intercept

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

Accuracy

A

A measurement close to the true value

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

Precision

A

The consistency between values obtained by repeated values

Seen to be precise if they cluster together

Really precise if all lie on line of best fit

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

Uncertainty for a single reading is at least

A

Half the resolution of the equipment

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

Uncertainty for repeated readings that are different can be taken as

A

Half the range of the readings

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

A reading is

A

A value found from a single judgement

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

A measurement

A

Requires the value to be taken from two readings or judgments

E.g.
Stopwatch
A non zero ended ruler
Extension of spring (original and extension)

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

Uncertainty of a reading

A

+/- 0.5 resolution

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

Uncertainty of a measurement

A

+/- 1 of the resolution

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

The uncertainty should be quoted to the same decimal places as…

A

The reading

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

Resolution

A

The smallest change in value that can be measured using the instrument

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

Resolution allows us to assess the

A

Minimum possible uncertainty

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

Tolerance

A

A percentage uncertainty quoted by the manufacturer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

With a digital measuring machine what is the uncertainty

A

Will be +/- the smallest division shown on the meter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Percentage uncertainty eq

A

Uncertainty/ value x100%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Combining uncertainties by adding them or subtracting them

A

Add the absolute uncertainties of each quantity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Combining the uncertainties by multiplying or dividing

A

Add the percentage uncertainties of each quantity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Combining uncertainties of a quantity is raised to a power

A

Multiply the percentage uncertainty by the power

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Table heading should include

A

Quantity/ units

In this format

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

In a table the number of significant figures/decimal places should be….

A

Consistent down the column

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How to write logarithmic headings for tables

A

Ln (quantity/ unit)

As ln/logs don’t have units of their own

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Significant figures should always be the same as

A

The smallest number of significant figures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Good experimental design

A

Design to limit uncertainty number (have as few as possible)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Parallax

A

A type of error that is created when looking at the scale from an angle
Makes measurement larger or smaller than true value

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What to remember not to do w a micrometer

A

Use The ratchet

Not to over tighten

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Percentage uncertainty of repeat measurements

A

1/2 range / mean value x100%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What can you do to decrease random error

A

Repeat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What does random error mean for precision

A

They reduce precision

40
Q

How precise an experiment is from the graph

A

How much the points scatter from the line of best fit

41
Q

Percentage difference between two values

A

Difference between two values / the average of the two values

x100%

42
Q

Percentage difference between an experimental value and a stated value

A

Difference between values/ stated value

x100%

43
Q

The use of multiple readings reduce the

A

Uncertainty

44
Q

In general the percentage uncertainty of each measurement will be

A

The same percentage uncertainty for the whole experiment

The overall uncertainty will be reduced significantly by measuring multiple measurements

45
Q

What can be used to reduce uncertainty and help determine precise measurements with rulers

A

A set square

46
Q

What piece of equipment can be used to help keep eye level on oscillating things

A

A plumbline

47
Q

To measure small angles what can we use

A

Trigonometry

48
Q

Why is trigonometry used to measure small angles

A

Because protractor would give rise to uncertainty of 10% if angle was 5* and it measured to nearest 0.5*
If you measure opposite and adjacent distances then can use tan angle

49
Q

Techniques for timing oscillations

A

Use a pointer to show when it passes a certain point
Don’t miscount oscillations
Don’t start timing initially
Try to time at least 20 oscillations

50
Q

Fiducial mark

A

A pointer

51
Q

Techniques for timing oscillations

A

Use a pointer to show when it passes a certain point
Don’t miscount oscillations
Don’t start timing initially
Try to time at least 20 oscillations

52
Q

Fiducial mark

A

A pointer

53
Q

3 reasons to use data loggers

A

Record data automatically
Can record data with v small intervals
Over long periods of time

54
Q

Sample rate

A

Number of readings taken per second

55
Q

Data logger can record several…

A

Variables simultaneously

56
Q

Graph goes through origin it is called

A

Directly proportional

57
Q

If graph doesn’t quite go through origin then…

A

It is still a linear relationship

58
Q

A result that doesn’t fit the general pattern and lies a long way from the line of best fit

A

An anomaly

An anomalous result

59
Q

Gradient how to calculate

A

Rise over run

BIG triangle!!!

60
Q

What can the uncertainty in a measurement on a graph be shown as

A

Error bars

61
Q

If there is uncertainty on both the x and y components then you need to draw an…

A

Error rectangle

62
Q

If you are plotting a log graph then what happens w error bars

A

Calculate logs of maximum and minimum values

Determine the error bars using these values

63
Q

To determine the uncertainty in a gradient

A

Three lines should be drawn on the graph
Line of best fit and…
The steepest line and shallowest gradient line that can be drawn using the bottoms of the error bars

Then find percentage uncertainty in gradient
(Highest grad-lowest grad)/gradient of line of best fit
X100%

64
Q

How to make an exponential graph linear

A

Take natural logs of all components

Ln

65
Q

Name as many of the 6 standard SI base quantities and units

A 
Length - meter (m)
Mass - kilogram (kg)
Time - seconds (s)
Electric current - amperes (A)
Temperature - Kelvin (K)
Amount of substance - mole (mol)
66
Q

Centi

c

A

X10 -2

67
Q

Milli m

A

X10 -3

68
Q

Micro m

‘. (Has a flick)

A

X10 -6

69
Q

Nano

n

A

X10 -9

70
Q

Pico

p

A

X10 -12

71
Q

Fento

f

A

X10 -15

72
Q

Kilo K

A

X10 3

73
Q

Mega M

A

X10 6

74
Q

Giga G

A

X10 9

75
Q

Tera T

A

X10 12

76
Q

How to exchange indices when they are made to a power

A

You times the indices as if they were in a bracket

77
Q

Significant figure number

A

The same as the smallest number that you are working with

78
Q

Linear relationship equation

A

y= mx+c

79
Q

Gradient is also known as

A

Rate of change

80
Q

What size triangle for a gradient

A

LARGE triangle

BIG triangle

81
Q

To calculate an instantaneous gradient

A

Draw a tangent at the point
Make big triangle
Calculate gradient from the triangle

82
Q

Mathematically how can gradient be found

A

Differentiation

83
Q

What kind of scale to use when you want a linear graph with an exponential relationship

A

Logarithmic scale

84
Q

Small angle approximation sin

A

Sin ° = °

85
Q

Small angle approximation cos °

A

Cos ° = 1 for small values of °

86
Q

Small angle approximation for tan °

A

Tan ° = °

87
Q

Converting from degrees to radians

A

Pie/ 180 x degrees

88
Q

Converting from radians to degrees

A

180/ pie x radians

89
Q

Avogadro number

A

6.02 x10 23

90
Q

Method for turning up a dial in an experiment to increase accuracy

A

Turn it up till result is found.
Then go over value and then come back down to find value again
Record and average

91
Q

Surface area of a sphere

A

4 pie r^2

92
Q

Surface area of a cylinder

A

2 pie r^2 + 2 pie r h

93
Q

An angle in radians equation

A

• = arc length/ radius

94
Q

Random error examples

A

Human reaction time
Changes in room temperature
Contact resistance of crocodile clips
Too quick changing readings- hard to read off quickly

95
Q

Vernier calliper measures to nearest

A

0.1 mm

96
Q

Micrometer measures to nearest

A

0.01 mm

Physics Practical (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions