Required Equations and units Flashcards
what is the equation to find weight?
weight = mass X gravitational field strength
W=mg
what is work done?
work done = force X distance (along line of action of the force)
W=Fs
what is the force applied to a spring?
force = spring constant X extension
F=ke
what is the moment of a force?
moment = force X distance(normal to direction of force)
M=Fd
what is pressure?
pressure= force normal to surface/ area of surface
p=F/A
what is the equation for distance travelled?
distance travelled=speed X time
s=vt
what is acceleration?
acceleration = change in velocity/ time taken
a=Δv/t
what is the equation for resultant force?
resultant force = mass X acceleration
F=ma
what is momentum?
momentum = mass X velocity
p=mv
what is kinetic energy?
kinetic energy = 0.5 X mass X (speed)²
Ek=1/2 m v²
what is gravitational potential energy?
gravitational potential energy = mass X gravitational field strength X height
Ep=mgh
what is power in terms of energy transferred?
power= energy transferred/time
P=E/t
what is power in terms of work done?
power = work done/time
P=W/t
what is efficiency in terms of energy transferred?
efficiency = useful output energy transferred/ total input energy transferred
what is efficiency in terms of power?
efficiency = useful power input/ total power input
what is wave speed?
wave speed = frequency X wavelength
v= fλ
what is charge flow?
charge = current X time
Q=It
what is potential difference?
potential difference = current X resistance
V=Ir
what is power in terms of potential difference?
power = potential difference X current
P=VI
what is power in terms of resistance?
power = current² X resistance
P=I² R
what is energy transferred in terms of power?
energy transferred = power X time
E=Pt
what is energy transferred in terms of pd and charge?
energy transferred = charge flow X potential difference
E=QV
what is density?
density = mass/volume
ρ =m/v
what is the unit for weight?
newtons
N
what is the unit for mass?
kilograms
Kg
what is the unit for gravitational field strength?
newtons per kilogram
N/Kg
what is the unit for work done?
Joule
J
what is the unit for force?
newton
N
what is the unit for distance?
metre
m
what is the unit for spring constant?
newtons per metre
N/m
what is the unit for extension?
metre
m
what is the unit for pressure?
pascal
Pa
what is the unit for area?
metre squared
m²
what is the unit for distance travelled?
metre
m
what is the unit for speed?
metres per second
m/s
what is the unit for time?
second
s
what is the unit for acceleration?
metres/second squared
m/s²
what is the unit for velocity?
metres/second
m/s
what is the unit for momentum?
kilogram metres per second
Kg m/s
what is the unit for power?
watt
W
what is the unit for wave speed?
metres/ second
m/s
what is the unit for frequency?
hertz
Hz
what is the unit for wavelength?
metre
m
what is the unit for charge?
coulomb
C
what is the unit for current?
ampere
A
what is the unit for potential difference?
volt
V
what is the unit for resistance?
ohm
Ω
what is the unit for density?
kilograms per metre cubed
Kg/m³
what is the unit for volume?
metre cubed
m³
what is the unit for energy?
joule
J