physics formulas

Question 1

density

Answer 1

mass/volume

Question 2

acceleration

Answer 2

(v-u)/t

Question 3

speed (general eq)

Answer 3

distance/time

Question 4

speed (from distance-time graph)

Answer 4

gradient of graph

Question 5

acceleration (from speed-time graph)

Answer 5

gradient of graph

Question 6

distance (from velocity-time graph)

Answer 6

area below graph

Question 7

work done

Answer 7

Fd

Question 8

unit for work done

Answer 8

J

Question 9

resultant force eq

Answer 9

F=ma

Question 10

kinetic energy

Answer 10

E = 1/2 mv^2

Question 11

gravitational potential energy

Answer 11

E = mgh

Question 12

density of liquids

Answer 12

pgh

Question 13

pressure formula

Answer 13

P = F/A

Question 14

weight formula

Answer 14

W=mg

Question 15

acceleration of free fall is: (with unit)

Answer 15

9.8N/kg

Question 16

why does an object float? (2 reasons)

Answer 16

1. density of object is lesser than the density of the liquid.
2. the size of the upthrust is greater or equal to the weight of the object

Question 17

what does the size of upthrust depend on? (2 things)

Answer 17

1. the density of the fluid
2. the volume of the liquid displaced.

Question 18

why is it better to take the average reading of one oscillation from multiple oscillations rather than just taking the time for one?

Answer 18

measuring the total time for multiple oscillations then dividing it by the number of oscillations reduced errors caused by human reaction time.

Question 19

How many types of physical quantities are there?

Answer 19

1. base quantites
2. derived quantites

Question 20

power eq (2)

Answer 20

P=W/t
P=E/t

Question 21

what are the types of quantities?

Answer 21

1. scalar quantites
2. vector quantites

Question 22

what is the difference between a scalar and vector quantity?

Answer 22

a scalar quantity only has magnitude whereas a vector quantity has both magnitude and direction

Question 23

How is terminal velocity reached?

Answer 23

terminal velocity is reached when the weight of the object is equal to the drag. initially, the weight of the object will be bigger than the drag, but as the object accelerates downwards, the drag gradually increases and the drag force eventually is the same as the weight force, and terminal velocity is reached.

Question 24

precautions to take when carrying out experiments to calculate density (3)

Answer 24

1. handle glassware carefully
2. dont pour water into the measuring cylinder when it is on the electric balance to prevent getting an electric shock.
3. Stand up during the whole experiment to react quickly to any spills.

Question 25

energy stores (8)

Answer 25

1. kinetic
2. gravitational potential
3. chemical
4. elastic
5. nuclear
6. electrostatic
7. internal
8. magnetic

Question 26

what is work done equal to? (not the formula)

Answer 26

change in energy

Question 27

name the types of energy resources

Answer 27

1. renewable
2. non-renewable

Question 28

name 3 types of renewable energy sources:

Answer 28

1. wind
2. geothermal
3. heat and light from sun

Question 29

name 2 types of non-renewable energy sources

Answer 29

nuclear and chemical energy

Question 30

energy efficiency eq

Answer 30

(useful energy output / total energy input) x 100

Question 31

state the law of reflection

Answer 31

i=r

Question 32

where is the image formed in a plane mirror and what type of image is it?

Answer 32

the image is formed behind the mirror and the image is virtual

Question 33

state snell’s law

Answer 33

n = sin i / sin r

Question 34

what is total internal reflection?

Answer 34

when the incident angle is greater than the critical angle, and the incident material is denser than the second material.

Question 35

eq to calculate critical angle

Answer 35

sin c = 1/n

Question 36

state the 2 types of lenses

Answer 36

1. converging lens
2. diverging lens

Question 37

how many types of images are there and what are they

Answer 37

2 types, real and virtual images

Question 38

Refractive index formula (2)

Answer 38

1. n = sin i/sinr
2. n = c/v