Physics Formulas (Physics for your future)

Charge (coulombs, C) = Current (amps, A ) x Time (seconds)

Current = Charge/ Time 

Time =Charge/ Current 

Potential difference (voltage , V)= Current x Resistance (ohms) 

V = I x R 

Electrical power (watts,W) = Current (amperes, A ) x Potential difference (volts, V ) 

P= I x V 

Energy transferred (joules, J ) = Current x Potential difference x Time (seconds)

E = I x V x t

Acceleration (m/s^2) = Change in velocity (m/s)/ time taken (s )

Written in symbols as 

a = v-u/t

(v = final velocity; u= initial velocity) 

If  there are forces in the same directions we add them together to get the resultant force

If there are forces acting in the opposite directions we subtract them to get the resultant force 

Force(N) = Mass(kg) x Acceleration (m/s^2) 

Often written as F= m x a

Weight (N) = Mass (kg) x Gravitational Field Strength (N/kg)

Weight is the measure of the pull of gravity on an object and can change 

GFS is 10N/kg on earth 

Stopping Distance = Thinking Distance + Braking Distance 

Momentum (kilogram metre per second, kg m/s) = Mass (kg) x Velocity (Metre per second) 

Momentum is a vector quantity that has a size and direction  so we have to state the direction of the momentum 

Changing momentum 

Force (N) = Change in momentum (kg m/s) / Time taken for change (s)

F= mv-mu/ t 

Work done (joules, J) = Force (Newtons N) x distance moved (in the direction of the force) (m) 

Work done is energy transferred from one form to another.

Power is the rate of doing work (measured in watts)

Power = work done (joules ,J )/ Time taken(seconds 

Work done stopping a vehicle is the breaking force x breaking distance ; Work done is equal to inital kinetic energy ( all of the vehicles kinetic energy is lost when it stops )

Gravitational Potential Energy

Gravitational Potential Energy (Joules, J) = Mass (Kg) x Gravitational Field Strength x Vertical Height (m)

Kinetic Energy 

Kinetic Energy (joule, J) = Mass (kg) x 0.5 x (Velocity)^2 m/s^2