Torque
A rotating object spins about the "axis of ___."
Is a stationary ladder leaning against a wall in rotational equilibrium?
What is Yes?
What is 30 turns?
A solid ball and a hoop of equal mass and diameter are spinning at the same speed. Which has more rotational energy?
What is hoop?
Does angular momentum have direction?
Will you spin faster with your arms extended or retracted?
Among the three answers, where is the best place to put the axis of rotation? 1) The center of mass 2) Where one force is canceled 3) The weighted average of the forces
Give angular velocity (w) in terms of linear velocity (v) and radius (r).
What is w = v/r?
The principle of "_______ of _____ momentum" is what causes phenomena like gyroscopic motion (a spinning tire attached to a string on only one end will stay upright).
What is conservation of angular momentum?
Can a system have net zero force and non-zero torque?
What is Yes
When is the Parallel Axis Theorem used?
When the center of mass is not on the rotational axis.
In a free-body diagram of a ball rolling down a slope, the arrow that represents the force of friction starts at this point.
What is the point of contact between the ball and the slope?
Disk A has radius r and mass m. Disk B has radius 2r and mass m/2. They rotate at the same speed. Which one has more rotational energy?
What is Disk B?
Give angular momentum (L) in terms of angular velocity (w) and moment of inertia (I).
What is L = Iw?
Give the torque equation that does not use Inertia.
What is T = r x F? (or torque = the cross product of distance and force)
If disturbed, the stable equilibrium will return to its original position. The unstable equilibrium will not.
A disc, a ball, and a hoop have equal diameters and equal mass. Rank their moments of inertia from least to greatest.
What is ball, disc, hoop?
Give the equation for rotational energy in terms of moment of inertia (I) and angular velocity (w).
What is RE = 1/2 Iw^2?
Given the x-axis is time, what should you plot on the y-axis so that the area under the curve is the change in angular momentum?
What is torque?
Give the torque equation that uses Inertia.
Give the formulation of the Parallel Axis Theorem.
I = I(com) + MD^2
Give the equation to calculate the rotational inertia of a system. Both the integral definition and the sum definition are acceptable.
I = Sum of mr^2
I = Integral of r^2 dm
For a ball rolling down a hill, PE = KE + RE. Rewrite this equation in terms of h, v, m, w, I, and g.
What is mgh = 1/2 mv^2 + 1/2 Iw^2?
What is L = r x p? (must say the cross product)