General

Question 1

Absolute Uncertainties

Answer 1

• The interval that a value is said to lie within, with a given level of confidence.
• (Range of measurements ÷ 2)
  Biggest - smallest

Question 2

Anomalies

Answer 2

• Data points that don’t fit the pattern of the data.
• You should determine why an anomalous result has occurred before removing it.
• Repeat readings help remove anomalies.

Question 3

Percentage Uncertainties

Answer 3

The uncertainty of a measurement, expressed as a
percentage of the recorded value.
𝑧 = 𝑥 ± 𝑦 𝛿𝑧 = 𝛿𝑥 + 𝛿𝑦

(gradient of line of best fit - gradient of line of worst fit) ÷ gradient of line of best fit

Question 4

Precision

Answer 4

• Precision is a measure of how close a measurement is to the mean value.
• It only gives an indication of the magnitude of random errors, not how close data is to the true value.

Question 5

Random Errors

Answer 5

• Random error is an unpredictable variation between measurements that leads to a spread of values about the true value.
• Random error can be reduced by taking repeat measurements.
• Examples include parallax errors.

Question 6

Repeatable

Answer 6

The same experimenter can repeat a measurement using the same
method and equipment and obtain the same value.

Question 7

Reproducible

Answer 7

the ability to achieve consistent results when an experiment is repeated by different experimenters using various methods or equipment.

Question 8

Resolution

Answer 8

The smallest change in a quantity that causes a visible change in the
reading that a measuring instrument records.

Question 9

Resolution of Forces

Answer 9

The splitting of a force into its horizontal and vertical
components.

Question 10

Scalar Quantities

Answer 10

A quantity that only has a magnitude, without an associated
direction. Examples include speed, distance and temperature.

Question 11

SI Units + prefixes

Answer 11

The standard units used in equations. They are: metres, kilograms, candela, seconds, amps, Kelvin and moles.
Tera (T)- 10^12
Giga (G)- 10^9
Mega (M)- 10^6
Kilo (k)- 10^3
Milli (m)- 10^-3
Micro (μ)- 10^-6
Nano (n)- 10^-9
Pico (p)- 10^-12
Femto (f)- 10^-15

Question 12

Systematic Errors

Answer 12

Causes all readings to differ from the true value by a fixed
amount. Systematic error cannot be corrected by repeat readings, instead a
different technique or apparatus should be used.

Question 13

Triangle of Forces

Answer 13

• A method of finding the resultant force of two forces is called the triangle of forces.
• The two forces are joined tip to tail, and the resultant is the vector that completes the triangle.

Question 14

Vector Quantities

Answer 14

• A quantity that has both a magnitude and an associated direction.
• Examples include velocity, displacement and acceleration.

Question 15

Vernier Scales

Answer 15

• The type of scale used on calipers and micrometers is called a vernier scale.
• It involves reading from a fixed scale and a moving scale to produce accurate measurements.

Question 16

Zero Errors

Answer 16

• A form of systematic error, caused when a measuring instrument doesn’t read zero at a value of zero, is called a zero error.
• This results in all measurements being offset by a fixed amount.

Question 17

Significant figures

Answer 17

• Copy the s.f. of the raw data which has the least s.f. (or 3 s.f. to play it safe)
• Zeros that come before all non-zero digits are not significant

Question 18

How to answer 6 markers

Answer 18

• Break down the question
• identify independent and dependent variables
• Equipment + measurements
• accuracy and errors?
• safety/controls?
  -formulas
• y=mx+c for analysis

Question 19

If they Introduce a new equation

Answer 19

Work in units

Question 20

Coplanar forces

Answer 20

• Act in the same plane