Rotational motion Flashcards
Equation for velocity involving angular velocity?
V=r x omega
Equation for acceleration involving angular acceleration?
a=r x alpha
Equation for angular momentum?
L=Ixomega
Equation for torque?
tau=I x alpha
Equation for rotational kinetic energy?
KE=1/2 x I x omega^2
Can we compare linear suvat to rotation?
Yes. S = x, U = omega_0, V = omega, a = alpha, t=t
Rotational work?
Integral of tau x dtheta
Rotational power?
P = tau x omega
When is angular momentum is conserved?
If there is no torque. Occurs when r and F are parallel
Another equation for torque involving AM?
tau = dL/dt
What happens when a pulley has mass?
The tension (T1-T2) generated a torque and torque needs to be considered in calculation of fricition
When does the magnitude of L change?
When torque has a component parallel to L
When does the direction of L change?
When torque has a component perpendicular to L
Angular momentum when object is translating and rotating?
L = (Rxp) + (Sum of r’ x p’)
Kinetic energy when an object is translating and rotating?
KE = 1/2Mv^2+1/2I0omega^2
What is the time of 1 revolution when rolling?
T=2pi/omega
Linear speed of CM when rolling?
Vcm=r x omega
What role does friction play when rolling?
Friction causes torque and needs to be considered in calculations
When hitting things, what changes?
Impulse can change both linear and angular momentum
What happens when impulse if through CM?
Whole body moves with velocity V and no angular motion
When is there no impulse effect?
When h x omega = velocity
Condition for pure rolling?
v=rw
When rolling down a slope, what is a good method to find certain values?
Use conservation of energy
What does friction cause?
A torque
