Chapter 1- Units

Question 1

All measurements in physics are described as

Answer 1

Physical quantities

Eg
Mass, length, time, temp, current, amount of a substance, luminous intensity

Question 2

All other measurements are derived from these

Answer 2

Base qualities

Eg
Speed (distance/time)

Question 3

What must always be paired with a measurement?

Answer 3

A quantity

Question 4

Base units are termed

Answer 4

SI units (system of international units)

Question 5

Length

Answer 5

Metre m

Question 6

Mass

Answer 6

Kilo gram kg

Question 7

Time

Answer 7

Second s

Question 8

Current

Answer 8

Ampere A

Question 9

Temperature interval

Answer 9

Kelvin K

Question 10

Amount of substance

Answer 10

Mole mol

Question 11

Derived units

Answer 11

For physical quantities derived from two or more base quantities

Question 12

Speed

Answer 12

Distance/ time

M/s

Question 13

Acceleration

Answer 13

^velocity/ ^time

M/s^2

Question 14

Force

Answer 14

Mass x acc

Newton
Kg m/s^2

Question 15

Pressure

Answer 15

Force/ cross sectional area

Pascal

Kg/m/s^2

Question 16

Work

Answer 16

W=Fx x

Joules

Question 17

Power

Answer 17

Work/ time

Watt (W)

Question 18

Charge

Answer 18

Current x time

Coulomb (C)

Question 19

Potential difference

Answer 19

Work / charge

Volt (V)

Question 20

Resistance

Answer 20

Velocity / current

Ohm (_/-_)

Question 21

Prefixes

Answer 21

For smaller or larger numbers

Eg micro milli

Question 22

Micro

Answer 22

X10-6

Question 23

Kilo

Answer 23

X10^3

Question 24

Milli

Answer 24

X10^-3

Question 25

Mega

Answer 25

X10^6

Question 26

Scalar

Answer 26

Magnitude only

Question 27

Vector

Answer 27

Magnitude and direction

Question 28

Adding scalars

Answer 28

Use normal maths

Question 29

Adding vectors

Answer 29

Use -ve and +ve for directions Can use scale drawings

Question 30

When adding components in a vector triangle

Answer 30

Use trigonometry

Question 31

Trig for sin

Answer 31

Sin(*) = opposite/ hypotenuse sOh

Question 32

Trig for cos

Answer 32

Cos(*)= adjacent/ hypotenuse cAh

Question 33

Trig tan rule

Answer 33

Tan(*)=opposite/ adjacent tOa

Question 34

Units

Answer 34

The actual units | Eg s,kg,m

Question 35

Quantities

Answer 35

The names of the things | Length, weight

Question 36

Speed SI

Answer 36

ms^-1

Question 37

Acceleration SI

Answer 37

ms^-2

Question 38

Force SI

Answer 38

kg ms^-1