introduction to physics

Question 1

what is physics?

Answer 1

• physics is a branch of science.
  uses experiments, measurements
  -maths to describe everything in the universe.
  -laws to predict everything in the universe
  -describes energy and matter

Question 2

what is energy?

Answer 2

ability to do work
light/kinetic/gravitational/electric/thermal

Question 3

what is matter?

Answer 3

tiny atoms and particles but also large structures like stars and galaxies

Question 4

how are energy and matter related?

Answer 4

energy and matter have a relationship that produces laws

Question 5

what are the two types of physics

Answer 5

theoretical and experimental

Question 6

what is theoretical physics?

Answer 6

theories of physics.
explains the results of experimental data and observations using maths and scientific concepts

Question 7

what is experimental physics?

Answer 7

creating a hypothesis (idea) and testing the hypothesis with experiments, observing the results and coming to a conclusion. potentially establishing new scientific laws to understand and predict something.

Question 8

how does physics link to chemistry?

Answer 8

chemistry involves atoms and molecules this links to molecular physics

Question 9

how does physics link to architecture?

Answer 9

structural ability of buildings, heating, lighting and cooling of building are all linked to physics

Question 10

how does physics link to geology?

Answer 10

the study of rocks, radioactive dating of rocks, earthquake analysis and heat transfer in earth

Question 11

how does biology link to physics?

Answer 11

heat/work/power in human body

Question 12

what is a quantity in physics

Answer 12

an amount, a measurement of something and its unit

Question 13

what is the units for length, volume, area, time,mass,speed,energy, charge and resistance

Answer 13

m/m cubed/m squared/s/kg/ (m/s) / j / coloumbs/ ohms

Question 14

what are SI units

Answer 14

6 main base units that all units are derived from.

Question 15

what are significant figures

Answer 15

the important values

Question 16

force (units and equation)

Answer 16

mass x acceleration - newton or kg m/s -2

Question 17

pressure (units and equation)

Answer 17

force /area - pascal or nm -2

Question 18

work done (units and equation)

Answer 18

force x distance - joule or Nm

Question 19

power (units and equation)

Answer 19

energy/time - watt or Js-1

Question 20

potential difference (units and equation)

Answer 20

energy/charge - JC-1 or volts

Question 21

resistance (units and equation)

Answer 21

voltage/current - ohm / VA -1

Question 22

charge (units and equation)

Answer 22

current x time - columb / As

Question 23

how to check if an equation is correct

Answer 23

units on the left = units on right
units must be homogenous

Question 24

what is a mistake?

Answer 24

-measuring incorrectly
-completing an experiment incorrectly
-we can rectify our mistakes by repeating our procedures in the right way

Question 25

what is an error?

Answer 25

-all measurements have errors -errors are the difference between a measured value and the true value for the quantity being measured

Question 26

what is a random error?

Answer 26

- affects precision -cant be completely removed -causes differences in measurements -random errors can not be corrected - take repeated measurements and report the mean value

Question 27

what is a systematic error?

Answer 27

-affects accuracy -due to faults in equipment or experimental method -causing the result to be too large/small by same amount each time.

Question 28

what are the causes of systematic errors?

Answer 28

the time/place a measurement is taken or faulty measurement tools

Question 29

what is accuracy?

Answer 29

a measure of how close the experimental values are to the known values . closer the measurements are to the known value more accurate it is

Question 30

what is precision?

Answer 30

a measure of how close the experimental measurements agree with each other.

Question 31

what is the combination of random and systematic errors called?

Answer 31

measurement uncertainty

Question 32

what is the interval in which the true value lies called?

Answer 32

uncertainty in the measurement

Question 33

what is the absolute uncertainty in the mean value of measurements ?

Answer 33

half the range of measurements

Question 34

what is fractional uncertainty?

Answer 34

uncertainty given as a fraction

Question 35

what is percentage uncertainty?

Answer 35

uncertainty given as a percentage

Question 36

what is the equation of percentage uncertainty?

Answer 36

percentage uncertainty= absolute uncertainty/ measured (mean) value x100

Question 37

what do you do to the uncertainty when you add or subtract quantities in an equation?

Answer 37

absolute uncertainty of each value is added together