Equations Flashcards
Speed
Speed(m/s)=Distance(m)/time(s)
Acceleration
Acceleration(m/s2)= (final sped-initial speed)/time
Force
Force(N)= mass(kg) x acceleration(m/s2)
Weight
Weight(N)= mass(kg) x gravity(N/kg)
Momentum
Momentum(kg m/s)= mass(kg) x velocity(m/s)
Force (involving momentum)
Force(N)= change in momentum(kg m/s)/ time taken(s)
Moment
Moment(Nm)= Force(N) x distance from pivot(m)
Orbital speed
Orbital speed(km/s) = 2× π ×orbital radius(km)/time period(s)
Power (electricity module)
Power(W)= current(A) x Voltage(V)
Energy transferred
Energy transferred(J)= current(A) x Voltage(V) x Time(s)
Charge
Charge(C)= current(A) x time(s) 36000C= 36 kC
Voltage
Voltage(V)= current(A) x resistance (ohm)
Efficiency
Efficiency(%)=(useful energy transferred(J)/total energy transferred(J)) x 100
Graviational potential energy
Gravitational potential energy(J) = mass(kg) x height (m) x gravity(m/s2)
Work done
Work done(J)= Force(N) x distance(m)
Power (energy resources module)
Power(W or J/s)= work done(J)/ time taken(s)
Kinetic energy
Kinetic energy= 0.5 x mass(kg) x speed2(m/s)
Potential Energy
Potential energy=mass x height x gravity(force x distance)
pressure in a solid
pressure (n/cm2 or Pa) = force (n) / surface area (cm2 or m2)
pressure in a liquid
pressure(Pa) = height (m) x density of fluid (kg/m3) x gravtational field strength (10)
density
density kg/m3 = mass (kg) / volume (m3)
volume of a sphere
(4/3) x pie r3
wave speed
wave speed (m/s) = wave length (m) x frequency (hz)
(waves module) frequency
frequency (hz) = 1/time period (s)
(waves module) time period
time period (s) = 1/ frequency (hz)
snell’s law
n (refractive index) = sin(i)/sin(r)
critical angle
sin(c) (critical angle) = 1/n (refractive index)
pressure and volume at a constant temperature
P(1) x V(1) = P(2) x V(2)
pressure and temperature at constant volume
P(1)/ T(1) = P(2)/T(2)
Voltage and turns in transformers
V(p)/V(s) = N(p)/N(s)
input power and out put power in transformers
V(p) x I(p) = V(s) x I(s)
