# Physics Formulas (Physics for your future)

• Created by: faholly21
• Created on: 11-06-15 11:40

## Charge and Current

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

Current Charge/ Time

Time =Charge/ Current

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## Voltage Current and Resistance

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

V = I x R

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## Power and Energy

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

P= I x V

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

E = I x V x t

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## Acceleration

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)

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## Resultant Forces

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

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## Force

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

Often written as F= m x a

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## Mass, Weight and Gravitational Field Strength

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

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## Stopping Distances

Stopping Distance = Thinking Distance + Braking Distance

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## Momentum

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

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## Work and Power

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 )

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## Potential and Kinetic Energy

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

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