Equations

Question 1

Work done

Answer 1

Work done(J)= force(N) x distance(m)

Question 2

Gravitational potential energy

Answer 2

GPE(J)= mass(kg) x gfs(N/kg) x height(m)

Question 3

Kinetic energy

Answer 3

KE(J)=0.5 x mass(kg) x velocity²(m/s)

Question 4

Elastic potential energy

Answer 4

EPE(J)= 0.5 x spring constant(N/m) x extension²(m)

Question 5

Efficiency

Answer 5

Efficiency=useful output/total input

Question 6

Energy transferred

Answer 6

Energy(J)=power(W) x time(s)

Question 7

Power wasted by an appliance

Answer 7

Total power input - useful power output

Question 8

Weight

Answer 8

Weight(N)= gfs(N/kg) x mass(kg)

Question 9

Specific heat capacity in an equation

Answer 9

Energy(J)= mass(kg) x shc(J/kg°C) x temp change(°C)

Question 10

Charge flow

Answer 10

Charge flow(C)= current(A) x time(s)

Question 11

Electrical Energy

Answer 11

Energy(J)= charge(C) x potential difference(V)

Question 12

Potential difference

Answer 12

Potential dif(V)= current(A) x resistance(Ω)

Question 13

Power

Answer 13

Power(W)= current(A) x potential dif(V)

Question 14

Power (electrical)

Answer 14

Power(W)= current²(A) x resistance(Ω)

Question 15

Density

Answer 15

Density(kg/m³)= mass(kg) / volume(m³)

Question 16

Specific latent heat and vaporisation

Answer 16

Specific latent heat and vaporisation(J/kg)= energy(J) / mass(kg)

Question 17

Pressure

Answer 17

Pressure(Pa)= force(N) / area(m²)

Question 18

Volume and pressure

Answer 18

Volume(1) x pressure(1) = volume(2) x pressure(2)

Question 19

Moment

Answer 19

Moment(Nm)= force(N) x distance(m)

Question 20

Distance

Answer 20

Distance(m)= speed(m/s) x time(s)

Question 21

Acceleration

Answer 21

Acceleration(m/s²)= change in velocity(m/s) / time taken (s)

Question 22

Resultant force

Answer 22

Resultant force(N)= mass(kg) x acceleration(m/s²)

Question 23

Inertial mass

Answer 23

Inertial mass= force / acceleration

Question 24

Momentum

Answer 24

Momentum(kg m/s)= mass(kg) x velocity(m/s)

Question 25

Power

Answer 25

Power(W)= work done(J) / time(s)

Question 26

Force

Answer 26

Force(N)= spring constant(N/m) x extension(m)

Question 27

Pressure due to column of liquid

Answer 27

Pressure(Pa)= height(m) x density(kg/m3) x gfs(N/kg)

Question 28

Velocity, acceleration, distance

Answer 28

(final velocity m/s)2 - (initial velocity)2 = 2 x acceleration(m/s2) x distance(m)

Question 29

Force

Answer 29

Force(N)= change in momentum(kg m/s) / time(s)

Question 30

Period

Answer 30

1 / frequency(Hz)

Question 31

Wave speed

Answer 31

Wave speed(m/s)= frequency(Hz) x wavelength(m)

Question 32

Magnification

Answer 32

Magnification= image height / object height

Question 33

Force on a conductor carrying a current

Answer 33

Force(N)= magnetic flux density x current(A) x length(m)