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
