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Physics Equations - GCSE Physics

Students should be able to select and apply the following equations from the Physics equation sheet.

Equations required for Higher Tier papers only are indicated by HT in the left hand column.

Equation numberWord equationSymbol equation
1weight = mass × gravitational field strength (g)W=mgW = m\,g
2work done = force × distance (along the line of action of the force)W=FsW = F\,s
3force applied to a spring = spring constant × extensionF=keF = k\,e
4moment of a force = force × distance (normal to direction of force)M=FdM = F\,d
5pressure = force normal to a surface ÷ area of that surfacep=FAp = \frac{F}{A}
6distance travelled = speed × times=vts = v\,t
7acceleration = change in velocity ÷ time takena=Δvta = \frac{\Delta v}{t}
8resultant force = mass × accelerationF=maF = m\,a
9 HTmomentum = mass × velocityp=mvp = m\,v
10kinetic energy = 0.5 × mass × (speed)²Ek=12mv2E_k = \tfrac{1}{2}\,m\,v^2
11gravitational potential energy = mass × gravitational field strength (g) × heightEp=mghE_p = m\,g\,h
12power = energy transferred ÷ timeP=EtP = \frac{E}{t}
13power = work done ÷ timeP=WtP = \frac{W}{t}
14efficiency = useful output energy transfer ÷ total input energy transfer
15efficiency = useful power output ÷ total power input
16wave speed = frequency × wavelengthv=fλv = f\,\lambda
17charge flow = current × timeQ=ItQ = I\,t
18potential difference = current × resistanceV=IRV = I\,R
19power = potential difference × currentP=VIP = V\,I
20power = (current)² × resistanceP=I2RP = I^2\,R
21energy transferred = power × timeE=PtE = P\,t
22energy transferred = charge flow × potential differenceE=QVE = Q\,V
23density = mass ÷ volumeρ=mV\rho = \frac{m}{V}
Equation numberWord equationSymbol equation
1 HTpressure due to a column of liquid = height of column × density of liquid × gravitational field strength (g)p=hρgp = h\,\rho\,g
2(final velocity)² – (initial velocity)² = 2 × acceleration × distancev2u2=2asv^2 - u^2 = 2\,a\,s
3 HTforce = change in momentum ÷ time takenF=mΔvΔtF = \frac{m\,\Delta v}{\Delta t}
4elastic potential energy = 0.5 × spring constant × (extension)²Ee=12ke2E_e = \tfrac{1}{2}\,k\,e^2
5change in thermal energy = mass × specific heat capacity × temperature changeΔE=mcΔθ\Delta E = m\,c\,\Delta\theta
6period = 1 ÷ frequencyT=1fT = \frac{1}{f}
7magnification = image height ÷ object height
8 HTforce on a conductor (at right angles to a magnetic field) carrying a current = magnetic flux density × current × lengthF=BIlF = B\,I\,l
9thermal energy for a change of state = mass × specific latent heatE=mLE = m\,L
10 HTpotential difference across primary coil ÷ potential difference across secondary coil = number of turns in primary coil ÷ number of turns in secondary coilVpVs=npns\frac{V_p}{V_s} = \frac{n_p}{n_s}
11 HTpotential difference across primary coil × current in primary coil = potential difference across secondary coil × current in secondary coilVpIp=VsIsV_p\,I_p = V_s\,I_s
12For gases: pressure × volume = constantpV=constantp\,V = \text{constant}