P1 and P2 Equations

Question 1

what is the equation for work done (energy transferred)?

Answer 1

Work done = Force applied X Distance moved (along the line of action of the force)

W = F x S
W = Joules
F = Newtons
S = Metres

Question 2

what is the equation for weight?

Answer 2

weight = mass x gravitational field strength
W = M x G

W = newtons (n)
M = kilograms (kg)
G = newtons per kilogram (N/kg)

Question 3

What is the equation for the change of gravitational potential energy store of an object?

Answer 3

gravitational potential energy = mass X gravitational field strength X height

Ep = M x G x H

Ep = joules (j)
M = mass (kg)
G = newtons per kilogram (N/kg)
H = metres (m)

Question 4

what is the equation for kinetic energy?

Answer 4

kinetic energy = 1/2 x Mass x Speed2(squared)

Ek = 1/2 x M x V2(squared)

Ek = joules (j)
M = kilograms (kg)
V2 = metres per second (m/s)2(squared) was

Question 5

What is the equation for elastic potential energy?

Answer 5

elastic potential energy = 1/2 x Spring constant x extension2(squared)

Ee = 1/2 x K x e2(squared)

Ee= joules (j)
K = newtons per metre (N/m)
e2(squared) = metres2 (m2)

Question 6

what are the equations for efficiency?

Answer 6

efficiency = useful output energy transfer/ total input energy transfer

efficiency = useful power output/ total power input

(x100%) to find a percentage for answer

Question 7

what is the equation for power of an appliance?

Answer 7

Power, P = energy transferred to appliance, E/ time taken for energy to be transferred, T

P = Watts (w)
E = Joules (j)
T = Seconds (s)

Question 8

what is the equation for wasted power?

Answer 8

power wasted = total power in - useful power out

Question 9

what is the equation for specific heat capacity?

Answer 9

specific heat capacity = energy transferred/ mass x temperature change

Or

energy transferred = mass X specific heat capacity X temperature change

energy transferred = E (joules, j)
mass = M (kilograms, kg)
specific heat capacity = C (joules per kilogram per degree celsius, J/kgC)
temperature change = (Celsius, C)