A-Level Physics Flashcards

Definition of radian

The measure of the angle subtended at the center of the circle when the radius is equal to the arc length/linear displacement.

Formula for angular speed

ω = dθ/dt = 2π/T

Formulae for tangential/linear speed

v = ωr

v = ds/dt

Formulae for centripetal acceleration

a_c = v²/r

a_c = ω²r

Formulae for centripetal force

F_c = ma_c

F_c = mv²/r

F_c = mω²r

Newton’s Law of Gravitation equation for the force between two point masses

F_g = GMm/r²

Newton’s Law of Gravitation definition

The force of attraction between two point masses is directly proportional to the product of their masses and inversely proportional to their separation squared.

Terms of a satellite in a geostationary orbit

1. Orbits from West to East (WE)

2. Orbits directly above the equator

3. Has and orbital period of 24 hours

Gravitational Field definition

Force per unit mass

Equation for gravitational field strength due to a point mass

g = GM/r² (m is mass of point mass pulling)

Define the gravitational potential at a point

The work done per unit mass in bringing a small test mass from infinity to the point.

Equation for T/K

θ/ °C + 273.15

Define specific heat capacity

The amount of thermal energy required to raise a substance by 1°C per unit mass.

Define specific latent heat

The amount of thermal energy required to change the state of a substance per unit mass without a change in temperature.

Give the equations of state for an ideal gas

pV = nRT

pV = NkT

What is the equation for the Boltzmann constant k?

R/N_A (N_A is Avogadro’s constant)

Give the basic assumptions of the kinetic theory of gases (hint: there are 5)

1. Gas particles are in continuous, random motion

2. Gas particles have negligible volume compared to the volume of the gas

3. There are negligible intermolecular forces between the particles, except during collisions

4. All collisions are perfectly elastic

5. Time of collisions are negligible in comparison with time between collisions

Formula for the average translational kinetic energy of a gas molecule.

3/2 kT

Define internal energy

The sum of a random distribution of kinetic and potential energies associated with the molecules of a system.

Equation for work done

W = pΔV (at constant pressure of surroundings)

First law of thermodynamics

ΔU = q + W

increase in internal energy

energy transferred to system by heating

work done on the system

Define electric field

Force per unit positive charge.

Equation for force on a charge in an electric field

F = qE

Equation for field strength of the uniform field between charged parallel plates

E = ΔV/Δd (V is potential difference)

Equation for force between two point charges in free space.

Coulomb’s Law

F = Q₁Q₂ /(4πε₀r²)

Electric field strength due to a point charge in free space

E = Q /(4πε₀r²)

Define electric potential at a point

The work done per unit positive charge in bringing a small test charge from infinity to the point.

Relate electric field at a point to the potential gradient at that point.

E = - potential gradient = -ΔV/Δd

Equation for electric potential in the field due to a point charge

V = Q /(4πε₀r)