2.1.1 Physical Quantities and Units

Question 1

What is a quantity?

Answer 1

A physical quantity has a numerical value and a unit to indicate a measurement of something.

Question 2

What are prefixes used to indicate?

Answer 2

Decimal submultiples or units.

Question 3

What is kgms-1?

Answer 3

Momentum, because it is mass x velocity. You can tell the equations of things based off of their SI base unit composition.

Question 4

How did the international scientific community agree on SI base units?

Answer 4

They agreed to adopt a single unit for each quantity.

Question 5

Give the SI unit and symbol for mass.

Answer 5

Kilogram, Kg

Question 6

Give the SI unit and symbol for length.

Answer 6

Metre, m

Question 7

Give the SI unit and symbol for time.

Answer 7

Second, s

Question 8

Give the SI unit and symbol for temperature.

Answer 8

Kelvin, big K

Question 9

Give the SI unit and symbol for electrical current.

Answer 9

Ampere, big A

Question 10

Give the SI unit and symbol for amount of substance.

Answer 10

Mole, mol

Question 11

Give the SI unit and symbol for luminous intensity.

Answer 11

Candela, cd

Question 12

Give the SI unit and symbol for acceleration.

Answer 12

Metres per second squared, ms^-2

Question 13

Give the SI unit and symbol for density.

Answer 13

Kilograms per cubic metre, kgm^-3

Question 14

Give the SI unit and symbol for electric charge.

Answer 14

Coulomb, big C

Question 15

Give the SI unit and symbol for energy.

Answer 15

Joule, big J

Question 16

Give the SI unit and symbol for force.

Answer 16

Newton, big N

Question 17

Give the SI unit and symbol for momentum.

Answer 17

Kilogram metres per second, Kgms^-1

Question 18

Give the SI unit and symbol for potential difference.

Answer 18

Volt, big V

Question 19

Give the SI unit and symbol for power.

Answer 19

Watt, big W

Question 20

Give the SI unit and symbol for pressure.

Answer 20

Pascal, Pa

Question 21

Give the SI unit and symbol for velocity.

Answer 21

Metres per second, ms^-1

Question 22

Abbreviation and standard form for the prefix: pico-

Answer 22

p, 10^-12

Question 23

Abbreviation and standard form for the prefix: nano-

Answer 23

n, 10^-9

Question 24

Abbreviation and standard form for the prefix: micro-

Answer 24

μ, 10^-6

Question 25

Abbreviation and standard form for the prefix: milli-

Answer 25

m, 10^-3

Question 26

Abbreviation and standard form for the prefix: centi-

Answer 26

c, 10^-2

Question 27

Abbreviation and standard form for the prefix: deci-

Answer 27

d, 10^-1

Question 28

Abbreviation and standard form for the prefix: kilo-

Answer 28

k, 10^3

Question 29

Abbreviation and standard form for the prefix: mega-

Answer 29

Big M, 10^6

Question 30

Abbreviation and standard form for the prefix: giga-

Answer 30

Big G, 10^9

Question 31

Abbreviation and standard form for the prefix: tera-

Answer 31

Big T, 10^12

Question 32

How do you check the homogeneity of an equation?

Answer 32

Check that the base units on each side of the equation are equal.

Question 33

What is crucial about homogeneity?

Answer 33

Having a homogeneous equation does not mean that it is correct, as the numbers could be wrong.