Flipping Physics Notes
Net work = change in kinetic energy (aka friction alot of the time)
Power = work / time = change in energy / time
All collisions linear momentum is conserved
Impulse - average force * time, area under force time curve
if there is no force, then there is no impulse, which means momentum is conserved
Kinetic energy is conserved in elastic collisions
Inelastic collisions kinetic energy decreases
1 revolution = 360 degrees or 2 pi rad
arc length = theta r
Torque = radius * force
Parallel Axis Therorem I = I_cm + MD²
torque = intertia * alpha
Translational kinetic energy = ½ m v ²
Rotational Kinetic Energy = ½ I omega²
Total kinetic energy = ½ mv² + ½ I omega²
Work = torque * theta
L (angular momentum) = inertia * omega
acceleration without slipping - only depends on theta, g, and the coefficient in front of inertia
at amplitude velocity is 0, acceleration is at max spring force is at max
equilibrium velocity is at max
period of a spring = 2 pi root (m / k)
restoring force of a spring is the spring force acting on the mass
period of a pendulum = 2 pi root (l / g)
restoring force of pendulum is component of weight
x = A cos (2 pi f t) or amplitude cos (2 pi frequency * time)
cosine = initial position is amplitude
sine = initial position is equilibrium
position time and acceleration time cos graphs are opposite of eachother
torricellis theorum v = root (2gh)
derived from “energy aaproach” (rho g h = ½ rho v²)
horizontal mass sptring system
½ k A² = ½ m vmax²
kA² = m vmax²
vmax = root (kA²/m) = A root (k/m)
Orbiting satellites
circular orbit - Mechanical energy and potential energy of the system is constant , kinetic energy and momentum of satellite is constant
elliptical orbit - mechanical energy is constant, potential energy is not of the system; satellites momentum is constant but the kinetic energy is not
both orbits have constant angular velocity but not constant tangential velocity
restoring force always points towards equilibrium