Planetary
A planet sweeps out equal areas in equal times because this physical quantity remains constant in orbit.
What is angular momentum?
To calculate linear momentum, you use mass; to calculate angular momentum, you use this rotational mass equivalent.
What is moment of Inertia?
During a collision with a ball and a spinning rod with no external torques, this quantity is conserved.
What is angular momentum?
This term describes the product of torque and the time interval over which it is acts.
What is angular impulse?
A spinning skater named Mr. Holloway pulls his arms inward, decreasing this quantity to spin faster.
What is the moment of inertia?
In an elliptical orbit, a planet reaches its highest orbital speed at this orbital position.
What is perihelion?
This vector quantity is required to change an object's angular momentum.
What is torque?
A moving object with linear momentum p passes a point of minimum distance r. This is its angular momentum about that point.
What is pr?
This rotational quantity equals the rate of change of angular momentum.
What is torque?
A system can only conserve angular momentum if this condition about external torques is true.
What is they are zero?
A satellite spirals slowly inward due to atmospheric drag. To conserve angular momentum, this orbital property must increase even though energy is being lost.
What is its orbital speed?
A freely rotating object doubles its moment of inertia. To conserve angular momentum, this must happen to its angular velocity.
What is it is cut in half?
Two identical disks are spinning on the same axle. One spins at ω and the other is at rest. If the top disk drops onto the bottom one and they stick, this is their new final angular velocity.
What is ω/2?
A 10 N⋅m torque acts on a wheel for 3 seconds. This is the resulting change in the wheel's angular momentum.
What is 30 kg⋅m2/s?
A rotating planet slowly loses mass as it ejects gas into space. If no external torques act, this quantity must remain constant for the planet gas system.
What is total angular momentum?
As a comet approaches the sun, its moment of inertia decreases dramatically. To conserve angular momentum, this happens to its angular velocity.
What is it increases?
Linear momentum is p=mv. For a point mass moving in a circle, this is the expression for its angular momentum.
What is mvr?
A clay ball is thrown and sticks to the end of a rotating rod. Angular momentum is conserved, but this type of energy is lost.
What is kinetic energy?
Applying a torque opposite a disk's direction causes its angular velocity to decrease until this occurs.
What is it reaches zero and reverses direction?
A star collapses from a red giant to a white dwarf. To conserve angular momentum, its rotation period must do this.
What is it decreases?
Earth suddenly shrinks to half its current radius while keeping its same mass. Assuming angular momentum is conserved, determine the new length of a day. (Assume Earth is a uniform sphere where I=2/5MR2)
What is 6 hours?
A rigid body's rotational kinetic energy triples while its moment of inertia stays constant, causing this proportional change in its angular momentum.
What is √3 (square root of 3)?
A 1 kg rock moving at 10 m/s hits and sticks to the rim of a 4 kg disk (radius 2m) that is initially at rest. Using conservation of angular momentum, determine the system's final angular velocity.
What is 1.67 rad/s?
A constant 5 N tangential force acts at a radius of 0.4 m on a freely rotating wheel for 4 seconds. This is the change in the wheel's angular momentum.
What is 8 kg⋅m2/s
A skater spins at 2.0 rev/s with her arms extended, giving her a moment of inertia of 3.0 kg⋅m2. She pulls her arms in, reducing her moment of inertia to 0.8 kg⋅m2. This is her new rotational frequency in revolutions per second.
What is 7.5 rev/s?