20:006 EXAM 2 FORMULAS

w = m × g g = 10 m/s2 1 m = 100 cm, 1 kg = 1000 grams

atmospheric pressure ≈ 100,000 Pa 1 Pa = 1 N/m2

Rotational momentum (J) J = I Ω I= rotational inertia Ω=rotational velocity

Torque τ = F L

Force = Pressure × Area force (F) FPressure (P) = =area (A) A

density (ρ) = mass / volume

Buoyant force = weight of displaced water = volume of object submerged in liters × 10 N/liter

weight of 1 liter of water = 10 N GPE = mgh KE = ½ mv2

heat (Q) = mass (m) × specific heat (c) × temperature change (∆T) in C Q mc T= ∆

( )5 329C FT T= −

9 325F CT T= +

273K CT T= +

Change in internal energy of a system = heat absorbed by system − work done by system

Heat into Engine = Work done by engine + Heat discarded by engine

in outQ W Q= +

in

WQ

=work done by engineEngine efficiency =heat into the engine

( )( )

fT

1frequency = period ( )

( )T

f1period =

frequency

spring force (N) = spring constant k (N/m) × stretch or compression in

m k x=springF

Mass-spring system 2 mTk

π= Pendulum 2 LTg

π=

“golden rule” vwave fλ=