Working as a Physicist Flashcards
1
Q
Name the seven base (SI) quantities.
A
Time Current Temperature Mass Luminous intensity Length Amount of substance
2
Q
What is the unit for time?
A
Seconds (s)
3
Q
What is the unit for current?
A
Amperes (A)
4
Q
What is the unit for temperature?
A
Kelvin (K)
5
Q
What is the unit for mass?
A
Kilogram (kg)
6
Q
What is the unit for luminous intensity?
A
Candela (cd)
7
Q
What is the unit for length?
A
Metre (m)
8
Q
What is the unit for amount of substance?
A
Mole (mol)
9
Q
List the prefixes from largest to smallest.
A
Tera Giga Mega Kilo Deci Centi Milli Micro Nano Pico Femto
10
Q
What does the tera prefix equal in standard form?
A
10^12
11
Q
What does the giga prefix equal in standard form?
A
10^9
12
Q
What does the mega prefix equal in standard form?
A
10^6
13
Q
What does the kilo prefix equal in standard form?
A
10^3
14
Q
What does the milli prefix equal in standard form?
A
10^-3
15
Q
What does the micro prefix equal in standard form?
A
10^-6
16
Q
What does the nano prefix equal in standard form?
A
10^-9
17
Q
What does the pico prefix equal in standard form?
A
10^-12
18
Q
What does the deci prefix equal in standard form?
A
10^-1
19
Q
What does the centi prefix equal in standard form?
A
10^-2
20
Q
What does the femto prefix equal in standard form?
A
10^-15
21
Q
What is an electronvolt, eV?
A
A small unit of energy
The work done moving an electron through a potential difference of 1V
22
Q
What is 1eV in J?
A
1.60 x 10^-19
23
Q
What is a kilowatt-hour, kWh?
A
A large unit of energy
The amount of energy used by a 1kW device in 1 hour
24
Q
What is 1kWh in J?
A
3.6 x 10^6
25
What is the general equation for something directly proportional to another thing?
y = kx (k being a constant)
26
What is the general equation for something inversely proportional to another thing?
y = k/x (k being a constant)
27
What is the approximate height of a human?
1.8m
28
What is the approximate speed of a car?
20ms^-1
29
What is the approximate wavelength of visible light?
6.00 x 10^-4
30
What is the approximate number of atoms in one gram of substance?
1 x 10^22
31
Which axis does the independent variable go on?
x-axis
32
Which axis does the dependent variable go on?
y-axis
33
What is a causal relationship?
Whether the effect you see is actually caused by changing the variable
34
What does a graph with the equation y = kx look like?
A straight diagonal line passing through the origin
35
What does a graph with the equation y = kx^2 look like?
A u-shape with no negative points
36
What does a graph with the equation y = k/x look like?
Two curves (half u-shapes) with asymptotes: one with positive x and y values, one with negative x and y values
37
What does a graph with the equation y = k/x^2 look like?
Two curves (half u-shapes) with asymptotes: one with positive x and y values, one with negative x and positive y values
38
What does a graph with the equation y = ke^±x look like?
Two curves (wide half u-shapes) that intercept and cross the y axis at k and never cross y=0
39
What does a graph with the equation y = ksin(x) look like?
A sinusoidal curve (transverse wave shape) that passes through the origin and peaks at k and troughs at -k
40
What does a graph with the equation y = kcos(x) look like?
A sinusoidal curve shifted π/2 to the left, crossing the y axis at k
41
What does a graph with the equation y = ksin^2(x) look like?
A sinusoidal curve that passes through the origin, peaks at k and never crosses y=0
42
What does a graph with the equation y = kcos^2(x) look like?
A sinusoidal curve shifted π/2 to the left, crossing the y axis at k and never crossing y=0
43
What is the difference between calculating the instantaneous rate of change to the approximate rate of change?
Instantaneous rate of change is found by finding the gradient of a tangent to the point on the curve
Approximate rate of change is found by finding the gradient of a line linking the point and another nearby point
44
What does the area under a velocity-time graph show?
Change in displacement
45
What does the area under a force-time graph show?
Impulse
46
What does the area under an acceleration-time graph show?
Change in velocity
47
What does the area under a force-displacement graph show?
Work done
48
What does the area under a charge-potential difference graph show?
Energy stored by a capacitator
49
How do you estimate the uncertainty of a value using equipment?
It is half the smallest division the equipment can measure, in either direction
50
How do you estimate the uncertainty of a value using significant figures?
Take one unit of the last significant figure that the value is given to and divide it by two
51
How do you turn an absolute uncertainty into a fractional uncertainty?
Divide the absolute uncertainty by the value that has been measured
52
How do you turn a fractional uncertainty into a percentage uncertainty?
Multiply the fractional uncertainty by 100
53
How do you combine uncertainties if you are adding or subtracting two or more values?
Add their absolute uncertainties together
54
How do you combine uncertainties if you are multiplying or dividing measurements?
Add their percentage uncertainties together
55
How do you combine uncertainties if you are raising a measurement to a power?
Multiply the percentage uncertainty by the power
56
How do you estimate the uncertainty in a mean?
Divide the range by two
57
What direction would error bars be if there is uncertainty in the values plotted on the y-axis?
Vertical
58
What direction would error bars be if there is uncertainty in the values plotted on the x-axis?
Horizontal
59
What direction would error bars be if there is uncertainty in the values plotted on the x-axis and y-axis?
Vertical and horizontal
60
What are the worst lines?
The steepest and shallowest lines that go through all the error bars on a graph
61
How do you calculate the uncertainty in a gradient using the worst lines?
Find the gradients of the worst lines
Find the difference between the gradient of the line of best fit and the gradient of each worst line
Use the one with the greatest difference as your uncertainty
62
How do you calculate the uncertainty in the intercept using worst lines?
Find the intercepts of the worst lines
Find the difference between the intercept of the line of best fit and the intercept of each worst line
Use the one with the greatest difference as your uncertainty
