equations

Question 1

weight

Answer 1

weight = mass x gravitational field strength
W = m x g

Question 2

work done

Answer 2

work done = force x distance (along a line of action of the force)
W = F x s

Question 3

force applied to a spring

Answer 3

force applied to a spring = spring constant x extension

F = K x e

Question 4

moment of a force

Answer 4

force x distance(normal to the direction of travel)

M = F x d

Question 5

pressure

Answer 5

force / area

p = F / A

Question 6

distance travelled

Answer 6

distance travelled = speed x time

s = v / t

Question 7

acceleration

Answer 7

acceleration = change in velocity / time taken
a = Δv / t

Question 8

resultant force

Answer 8

resultant force = mass x acceleration

F = m x a

Question 9

momentum

Answer 9

momentum = mass x velocity
p = m x v

Question 10

kinetic energy

Answer 10

kinetic energy = 0.5 x mass x (speed)²

Ek = 1/2m x v²

Question 11

gravitational potential energy

Answer 11

gravitational potential energy = mass x gravitational field strength x height
Ep = m x g x h

Question 12

power 1

Answer 12

power = energy transferred / time
P = E / t

Question 13

power 2

Answer 13

power = work done / time
P = W / t

Question 14

efficiency 1

Answer 14

useful output energy transfer / total input energy transfer

Question 15

efficiency 2

Answer 15

useful power output / total power input

Question 16

wave speed

Answer 16

wave speed = frequency x wavelength

v = f x λ

Question 17

charge flow

Answer 17

charge flow = current x time

Q = I x t

Question 18

potential difference

Answer 18

potential difference = current x resistance

V = I x R

Question 19

power 3

Answer 19

power = potential difference x current 
P = V x I

Question 20

power 4

Answer 20

power = (current)² x resistance 
P = I² x R

Question 21

energy transferred 1

Answer 21

energy transferred = power x time

E = P x t

Question 22

energy transferred 2

Answer 22

energy transferred = charge flow x potential difference

E = Q x V

Question 23

density

Answer 23

density = mass / volume 
p = m / v

Question 24

change in thermal energy

Answer 24

change in thermal energy = mass x specific heat
latency x temperature
change
ΔE = MCΔθ

Question 25

power 3

Answer 25

power = current² x resistance 
P = I² x R