Flashcards
Science equations
Cards in this deck (11)
- 1Efficiency = useful energy out ___________ Total energy in X 100%Use when working out how efficient equipment is ( light bulbs ) - measuring how much energy is conserved in a process. Energy may be lost to heat or vibration as waste.
Remember to express as a percentage - 2E= m x c x O Energy transferred =mass x specific heat capacity x temperature changeEnergy transferred = joules (J )
Mass ( g)
Temperature change (0*c) - 3E= p x t Remember PET E- energy transferred P- power T-timeElectrical energy transferred- affecting factors = the power and the time period switched on.
Measured in kWh - 4Wave speed = frequency x wavelength ( Maddie B song )V = speed (metre per second )
f = frequency (hertz)
Upside down Y = wavelength (metres) - 5F = m x a F = resultant force M=mass A= acceleration Acceleration = force ——— MassRea
- 6A= v - u ____________ divide T A=acceleration V=final velocity U=initial velocity T=time takenAcceleration = how quick the velocity of an object changes - it has a magnitude and direction ( not the same direction as the velocity )
- 7W=m x g W=Weight M=mass G=gravitational field strengthWeight is defined by force of gravity on the object - measured in Newton’s
- 8F= k x e F= force K= spring constant E= extensionHookes law - typically measured in metres
Spring contant - Newton’s per metre - 9W= F x d W=work done F= force applied D=distance moved in the direction of the forceWhen work is done - energy is transferred form one place to another.
Power is a measure of how quickly the work is done - power = work done //// divide by time taken - 10Ep = m x g x h Ep - change in gravitational potential energy M- mass G- gravitational field strength H- change in heightGPE - joules ( J ) = used for work done
Weight = mg
Distance = Height ( h )
GPE = mgh - 11Ek = 0.5 x m x v2 Ek= Kinetic energy M = mass V= speedKinetic energy- The energy possesses by its motion