Equations Flashcards
Speed
D/t
Acceleration
Change in velocity/time
Moment
Force x perpendicular distance
Weight
Mas x gravity
Impulse
Force x time =change in momentum
Momentum
Mass x velocity
Force
Mass x acceleration
Conservation of momentum
Mass x (change in velocity/time) = -mass x (change in velocity/ time)
Hookes law
F=kx or =ke
Work done or stored in a spring
W=1/2 x k x e^2
Kinetic energy
1/2x mass x velocity^2
Gravitattional potential
Mass x gravity x change in height
Pressure
F/a
Pressure in liquid
P=hpg=depth x density x gravity
Density
Mass/vol
Thermal capacity
Mass x specific heat capacity= mc
Change in energy when heating
Mass x specific heat capacity x change in temp
Energy to change state
Mass x specific latent heat
Frequency (of a wave)
1/time period (S)
Speed of a wave
Wavelength (m) x frequency (/s)
Refractive index
= speed of light in vacum/ speed of light in medium= c/v
=sini/sinr=
=n1sin01=n2sin02
=1/sin(critical angle)
Charge
It
V=
Ir
Power
Iv
Energy
Ivt= qv= charge x pd
Series voltage
Vtot=v1+v2
Current in series
Itot= I1=I2
Resistance in series
Rtot=R1+R2
Voltage in parallel
Vtot=V1+V2
Current in parallel
Itot=I1+I2
Resistance in parallel
1/Rtot=1/R1 +1/R2
Resistive heating
P=I^2 X R
Power in transformers
Pp=Ps
IpVp=IsVs
Number of turns in coil - transformers
Np/Ns=Vp/Vs
Right thumb rule
Thumb=direction of current
Curled hand=magnetic field (in concentric circles)
Left hand rule
Motor :
thumb= force (movement)
1st finger= field direction
2nd finger= current direction
Right hand rule
Generator:
Thumb= motion
1st finger= field direction
2nd finger= current direction
1 watt
1 joule
1Nm
1 joule
1 joule
1 watt/Nm
Voltage in potential divider circuit
Vout=Vin x (R/Rtot)
