Equations that you need to know and use for the Physics Terminal exam
Please see the end of this document for the equations that will be given to you. Double award students do not
need to know equations labelled TRIPLE.
Section 1: Forces and Motion
1. Average speed equation. Units: average speed in (m/s), distance in (m) and time (s)
2. The acceleration equation. Units: acceleration (m/s2), time in (s) and velocity in (m/s)
3. The F = ma equation, Units: Force in (N), acceleration (m/s2), and mass (kg)
4. The equation for WEIGHT. Units: weight (N), mass (kg) and g (m/s 2)
5. The momentum equation (TRIPLE). Units: momentum in (kgm/s), mass (kg) and velocity (m/s)
6. Equation to calculate a moment. Units: moment in (Nm), force (N), and distance (m).
The Energy Model
1. The efficiency equation. Units: ensure that energy output and input have the same units of energy Joules (J).
Please note that MJ = 1000 000 J, 1kJ = 1000J and1 mJ =0.00J
2. The work done equation. Units: Work done in Joules (J), force in Newton’s (N), and distance in (m)
3. The gpe equation. Units: gravitational potential energy in Joules (J), mass in (kg), g in (m/s 2) and height in (m)
4. The KE equation. Units: kinetic energy in Joules (J), mass in (kg) and speed in (m/s)
Current and Voltage
The relationships between charge in Coulombs (C), current in Amps (A), voltage in Volts (V), resistance in
Ohms () and electrical power in Watts (W), with time in seconds (s) :
1. Charge = current x time
Q = It
2. Voltage = current x resistance
V = IR
3. Electrical power = Voltage x current
P=IV
Waves
1. The relationship between the wave speed (m/s), frequency (Hertz, Hz) and wavelength (metres, m):
Wave speed
= frequency x wavelength
v
= f
2. The relationship between the refractive index, n (no units), the angle of incidence, i, in degrees and the angle of
refraction, r, in degrees:
n 
sin( i )
sin( r )
3. The relationship between the refractive index, n (no units), and the critical angle c, in degrees:
sin (c) =
1
n
Solids, liquids and gases
The following equations use the following with units: Density (kg/m3), mass (kg), volume (m3), Pressure (Pascal, Pa), Force
(N), area (m2), height (m) and acceleration due to gravity (m/s 2)
1. Equation linking density, mass and volume
2. Equation linking pressure, force and area
3. Equation linking pressure difference, height, g and density
Magnets and Electromagnets (MEM)
1. (Triple) Equation linking primary and secondary voltages (in Volts) to primary and secondary turns (in turns)
2. (Triple) Equation linking input power (in Watts, W) to output power (in Watts, W) via equation IV where I is the
current in Amps, A and V is the voltage in Volts, V.
EQUATIONS GIVEN ON THE PAPER
These are the equations that will be given to you on a separate page of the exam paper
The units:
a. For p1 x V1 = p2 x V2; you can use any unit for pressure and volume as long as you use the same units for pressure
1 and pressure 2, and the same units for volume 1 and volume 2
b. For
; p must be in Pascal’s and T must be in Kelvin so remember that [T in Kelvin = T in oC + 273]
c. Radius must be in metres, m
d. For Power = W/t, W=work done (the energy transferred in Joules, J) and t = time in seconds, s.
e. For f=1/T, f is the frequency in Hertz (Hz) and T is the time period in seconds, s.