Reference Guide & Formula Sheet for Physics Dr. Hoselton & Mr. Price
Version 5/12/2005
#3 Components of a Vector if V = 34 m/sec ∠48°
then
Vi = 34 m/sec•(cos 48°);
and
VJ = 34 m/sec•(sin 48°)
#4 Weight = m•g g = 9.81m/sec² near the surface of the Earth = 9.795 m/sec² in Fort Worth, TX
Density = mass / volume () 3:/ kgmunit V m= ρ #7 Ave speed = distance / time = v = d/t Ave velocity = displacement / time = v = d/t Ave acceleration = change in velocity / time
#8 Friction Force FF = µ•FN If the object is not moving, you are dealing with static friction and it can have any value from zero up to µs FN If the object is sliding, then you are dealing with kinetic friction and it will be constant and equal to µK FN
#9 Torque τ = F•L•sin θ Where θ is the angle between F and L; unit: Nm
#11 Newton's Second Law Fnet = ΣFExt = m•a
#12 Work = F•D•cos θ Where D is the distance moved and θ is the angle between F and the direction of motion, unit : J
#16 Power = rate of work done
unit : watt
Efficiency = Workout / Energyin Mechanical Advantage = force out / force in M.A. = Fout / Fin
#19 Constant-Acceleration Linear Motion v = vο + a•t x (x-xο) = vο•t + ½•a•t² v v ² = vο² + 2•a• (x - xο) t (x-xο) = ½•( vο + v) •t a (x-xο) = v•t - ½•a•t² vο
#20 Heating a Solid, Liquid or Gas Q = m•c•∆T (no phase changes!) Q = the heat added c = specific heat. ∆T = temperature change, K #21 Linear Momentum momentum = p = m•v = mass • velocity momentum is conserved in collisions
#23 Center of Mass – point masses on a line xcm = Σ(mx) / Mtotal
#25 Angular Speed vs. Linear Speed Linear speed = v = r•ω = r • angular speed
#26 Pressure under Water P = ρ•g•h
h = depth of water ρ = density of water
#28 Universal Gravitation
2 12 r mmFG = G = 6.67 E-11 N m² / kg²
#29 Mechanical Energy PEGrav = P = m•g•h KELinear = K = ½•m•v²
#30 Impulse = Change in Momentum F•∆t = ∆(m•v)
#31 Snell's Law n1•sin θ1 = n2•sin θ2 Index of Refraction n = c / v c = speed of light = 3 E+8 m/s
#32 Ideal Gas Law P•V = n•R•T
n = # of moles of gas R = gas law constant = 8.31 J / K mole.
#34 Periodic Waves v = f •λ f = 1 / T T = period of wave
#35 Constant-Acceleration Circular Motion ω = ωο + α•t θ θ−θο= ωο•t + ½•α•t² ω ω2 = ωο2 + 2•α•(θ−θο) t θ−θο = ½•(ωο + ω)•t α θ−θο = ω•t - ½•α•t² ωο
time WorkPower =
Reference Guide & Formula Sheet for Physics Dr. Hoselton & Mr. Price Page 2 of 8
Version 5/12/2005
#36 Buoyant Force - Buoyancy FB = ρ•V•g = mDisplaced fluid•g = weightDisplaced fluid ρ = density of the fluid V = volume of fluid displaced
