physics formulas

Question 1

average speed

Answer 1

v = total distance/total time

Question 2

acceleration

Answer 2

a= final velocity-initial velocity / time

Question 3

distance

Answer 3

area under speed-time graph

Question 4

acceleration of free fall

Answer 4

a=10m/s2

Question 5

gravitational field strength

Answer 5

g=10N/kg

Question 6

weight

Answer 6

W=mg

Question 7

density

Answer 7

density=mass/volume

Question 8

pressure

Answer 8

pressure=force/area

Question 9

resultant force

Answer 9

f=ma

Question 10

work done

Answer 10

W=Fd

Question 11

kinetic energy

Answer 11

Ek=1/2 mv2

Question 12

gravitational potential energy

Answer 12

Ep=mgh

Question 13

power

Answer 13

P=E/T

Question 14

moment of a force about a point

Answer 14

moment=force x perpendicular distance

Question 15

wave speed

Answer 15

v=f x λ

Question 16

speed of sound by direct measurement

Answer 16

v=d/t

Question 17

speed of sound by echo

Answer 17

v=2d/t

Question 18

refractive index(angle)

Answer 18

n=sin i/sin r

Question 19

refractive index(speed)

Answer 19

n=speed of light in vacuum/speed of light in medium

Question 20

current

Answer 20

I=Q/t

Question 21

charge

Answer 21

Q=I x t

Question 22

emf

Answer 22

E=W/Q

Question 23

potential difference

Answer 23

V=W/Q

Question 24

resistance

Answer 24

R=V/I

Question 25

effective resistance (in series)

Answer 25

R=R1+R2+R3

Question 26

effective resistance (in parallel)

Answer 26

1/R = 1/R1 + 1/R2 +1/R3

Question 27

electric power

Answer 27

P=I x V

Question 28

electrical energy

Answer 28

E=P x t

Question 29

cost of energy

Answer 29

cost= E x unit cost
1kW=1000W
1h=60 x 60s
1h=60 min