Q. A rigid body is rotating about a fixed axis with an angular velocity ω. If the moment of inertia of the body is I, what is the angular momentum of the body?
A.Iω
B.ω/I
C.I/ω
D.Iω^2
Solution
Angular momentum L = Iω, where I is the moment of inertia and ω is the angular velocity.
Q. A rigid body is rotating about a fixed axis. If the moment of inertia of the body is I and it is rotating with an angular velocity ω, what is its angular momentum?
A.Iω
B.I/ω
C.Iω^2
D.ω/I
Solution
Angular momentum L = Iω, where I is the moment of inertia and ω is the angular velocity.
Q. A rigid body rotates about a fixed axis with an angular velocity ω. If the moment of inertia of the body is I, what is the angular momentum of the body?
A.Iω
B.ω/I
C.I/ω
D.Iω^2
Solution
Angular momentum L = Iω, where I is the moment of inertia and ω is the angular velocity.
Q. A rotating disc has an angular velocity of ω. If the radius of the disc is doubled while keeping the mass constant, what happens to the angular momentum?
A.It doubles
B.It remains the same
C.It quadruples
D.It halves
Solution
Angular momentum L = Iω, where I is the moment of inertia. If radius is doubled, I increases by a factor of 4, but ω decreases by a factor of 2, so L remains the same.
Q. A rotating object has an angular momentum of L. If its angular velocity is doubled and its moment of inertia remains constant, what will be the new angular momentum?
A.L
B.2L
C.4L
D.L/2
Solution
Angular momentum L = Iω, if ω is doubled, L becomes 2I(2ω) = 4L.
Q. A rotating object has an angular momentum of L. If its moment of inertia is doubled while keeping the angular velocity constant, what will happen to its angular momentum?
A.It doubles
B.It halves
C.It remains the same
D.It becomes zero
Solution
Angular momentum L = Iω; if I is doubled and ω remains constant, L remains the same.
Q. A rotating object has an angular momentum of L. If its moment of inertia is halved and its angular velocity is doubled, what is the new angular momentum?
Q. A satellite is in a circular orbit around the Earth. What is the angular momentum of the satellite if its mass is m, its orbital radius is r, and its orbital speed is v?
A.mv^2/r
B.mvr
C.mr^2
D.mv
Solution
Angular momentum L = mvr, where v is the orbital speed and r is the radius of the orbit.
Q. A solid sphere of mass M and radius R is rolling without slipping on a horizontal surface. What is the expression for its total angular momentum about its center of mass?
A.(2/5)MR^2ω
B.MR^2ω
C.MR^2
D.0
Solution
Total angular momentum L = Iω, where I = (2/5)MR^2 for a solid sphere.
Q. If a body is rotating with an angular momentum L and its moment of inertia is halved, what will be the new angular momentum if the angular velocity remains constant?
A.L
B.2L
C.L/2
D.4L
Solution
Angular momentum L = Iω; if I is halved and ω remains constant, L remains L.
Q. If a child sitting on a merry-go-round moves from the center to the edge, what happens to the angular momentum of the system if no external torque acts?
A.Increases
B.Decreases
C.Remains constant
D.Becomes zero
Solution
Angular momentum remains constant if no external torque acts, according to the conservation of angular momentum.
