formulas Flashcards
force
force= mass x acceleration
weight
weight= mass x gravity
velocity
velocity (speed) = distance/ time
acceleration
change in velocity/ change in time
density
density= mass/ volume
gas laws
1/ volume
OR
p1v1=p2v2
power
power= work done/ time taken
OR
change in energy/ time
pressure
pressure= force/ area
pressure in liquids
pressure= density x gravity x depth
current
current= charge/ time
potential difference
p.d.= work done/ charge
e.m.f.
e.m.f.= work done/ charge
voltage
voltage= current x resistance
resistance
resistance= voltage/ current
power
(elec.)
power= current x voltage
energy
energy= voltage x current x time
heat energy
heat energy= mass x specific heat capacity x change in temp.
efficiency
efficiency= (useful energy output/ energy input) x 100
wave speed
wave speed= frequency x wavelength
frequency (waves)
frequency= number of oscillations/ time
OR
1/ time for 1 oscillation
refractive index
sin i/ sin r
OR
v1/ v2
OR
1/ sin C
speed of light in a vacuum
3.0x10ˆ8 m/s
speed of sound in air
330 to 350 m/s
audible human range
20 to 20,000 Hz
