1.1 Basic Physics

Question 1

Symbol for mass

Answer 1

m

Question 2

Symbol for length

Answer 2

l

Question 3

Symbol for time

Answer 3

t

Question 4

Symbol for electric current

Answer 4

I

Question 5

Symbol for temperature

Answer 5

T

Question 6

Symbol for amount of substance

Answer 6

n

Question 7

Symbol for luminous intensity

Answer 7

L

Question 8

Unit of mass

Answer 8

kilogram (kg)

Question 9

Unit of length

Answer 9

metre (m)

Question 10

Unit of time

Answer 10

second (s)

Question 11

Unit of electric current

Answer 11

ampere (A)

Question 12

Unit of temperature

Answer 12

kelvin (K)

Question 13

Unit of amount of a substance

Answer 13

mole (mol)

Question 14

Unit of luminous intensity

Answer 14

candela (cd)

Question 15

Equation for area

Answer 15

area=length*breadth

Question 16

Unit of area

Answer 16

m^2

Question 17

Equation for change of speed or velocity

Answer 17

change of speed=final velocity-initial velocity

Question 18

Unit of change of speed/velocity

Answer 18

ms^-1

Question 19

Equation for acceleration

Answer 19

acceleration=change of velocity/time a=Δv

Question 20

Symbol for acceleration

Answer 20

a

Question 21

Unit of acceleration

Answer 21

ms^-2

Question 22

symbol for change of speed/velocity

Answer 22

Δv

Question 23

Equation for Force

Answer 23

Force=mass*acceleration F=ma

Question 24

Symbol for force

Answer 24

F

Question 25

Unit of force

Answer 25

Newtons (N) (kgms^-2)

Question 26

Equation for work

Answer 26

Work=Force*distance

Question 27

Unit of work

Answer 27

Joules (J) (kgm^2s^-2)

Question 28

Equation for Power

Answer 28

Power=work/time

Question 29

Unit of power

Answer 29

Watt (W) (kgm^2s^-3)

Question 30

What are the rules for homogentity?

Answer 30

1. Two quantities can only be added together if the have the same units, and the answer has the same units.
2. An equation is homogeneous only if the units of the two sides are the same.

Question 31

What is a vector quantity?

Answer 31

A vector quantity has magnitude and direction, eg Force

Question 32

What is a scalar quantity?

Answer 32

A scalar quantity just has magnitude eg mass

Question 33

What is resultant force?

Answer 33

The combined effect of two or more forces is called the resultant force (Fres) [res is subscript]

Question 34

How do you calculate Resultant Force?

Answer 34

Use the cosine rule of Pythagoras’ theorum

Question 35

Symbol for Resultant Force

Answer 35

Fres [res is subscript] or ΣF

Question 36

What is displacement?

Answer 36

The distance and direction from A to B, in a straight line/ eg point A is 9cm W of point B

Question 37

Equation for velocity

Answer 37

velocity=displacement/time

Question 38

Unit for velocity

Answer 38

metres per second in a stated direction (ms^-1 at compass point)

Question 39

Equation for acceleration

Answer 39

acceleration=change of velocity/time a=Δv/Δt

Question 40

How do you add and subtract vectors?

Answer 40

Use nose-to-tail method

Question 41

What is “resolving” a force?

Answer 41

Calculating the horizontal and vertical components

Question 42

Equation for Density

Answer 42

Density=mass/volume ρ=m/V

Question 43

Symbol for density

Answer 43

ρ

Question 44

Unit of Density

Answer 44

kgm^-3 or gcm^-3

Question 45

Approximate density of air

Answer 45

1.29ρ/kgm^-3 0.00129ρ/gcm^-3

Question 46

Approximate density of water

Answer 46

1000ρ/kgm^-3 1.00ρ/gcm^-3

Question 47

Approximate density of brick

Answer 47

2300ρ/kgm^-3 2.30ρ/gcm^-3

Question 48

Approximate density of petrol

Answer 48

880ρ/kgm^-3 0.88ρ/gcm^-3

Question 49

Approximate density of steel

Answer 49

7900ρ/kgm^-3 7.90ρ/gcm^-3

Question 50

Approximate density of aluminium

Answer 50

2800ρ/kgm^-3 2.80ρ/gcm^-3

Question 51

Approximate density of mercury

Answer 51

13600ρ/kgm^-3 13.6ρ/gcm^-3

Question 52

Approximate density of gold

Answer 52

19300ρ/kgm^-3 19.3ρ/gcm^-3

Question 53

What would the width of 1 tonne of interstellar space be?

Answer 53

10^6km

Question 54

What would the width of 1 tonne of red giant star be?

Answer 54

100m

Question 55

What would the width of 1 tonne of the sun be?

Answer 55

0.89m

Question 56

What would the width of 1 tonne of a white dwarf be?

Answer 56

8.9mm

Question 57

What would the width of 1 tonne of a neutron star be?

Answer 57

15µm (micro metres)

Question 58

How do you convert cm^3 to m^3?

Answer 58

1 cm^3 = 1*10^6 m^3

Question 59

How do you convert density from kg-g?

Answer 59

1000kgm^-3 = 1.00gcm^-3

Question 60

Define torque/ the moment of a force

Answer 60

The product of a force multiplied by the perpendicular distance from the line of action to the pivot.

Question 61

Unit of moment/Torque

Answer 61

Newtons per metre (Nm)

Question 62

Symbol for torque/moment of a force

Answer 62

t

Question 63

What is the principal of moments?

Answer 63

For a body to be in equilibrium under the action of a number of forces, the resultant moment about any point is zero.

Question 64

Define equilibrium

Answer 64

A body is in equilibrium if it is moving and rotating at a constant rate. In order for this to happen:

1. The resultant force on the object must be zero.
2. The resultant moment around any point must be zero.

Question 65

How would you measure the density of a regular solid?

Answer 65

Calculate the volume using
Volume of a cuboid= lbh
Volume of a cylinder = Al = π r^2 l = (π r^2 l)/4

Question 66

How would you measure the density of a irregular solid?

Answer 66

Submerge the solid in a measuring cylinder of water and measure the displacement of the water.