Question

Angular Momentum help?

Answer 1

What is the angular momentum L of a rotating wheel with mass m, radius r, moment of inertia I, angular velocity ω, and velocity v of its outer edge?

Answer 2

mvr

mωr

Iω

mIω

Answer 3

momentum is the product of mass times velocity

angular momentum is the product of (mass) time angular velocity ... i think there would be just 2 factors for that but i cant be certain

Answer 4

http://hyperphysics.phy-astr.gsu.edu/hbase/amom.html

Answer 5

Which of the following is true for the angular momentum of a rotating bicycle wheel?

Answer 6

The net torque acting on the wheel was zero.

There was net torque acting on the disk.

The angular velocity remained unchanged.

The moment of inertia of the disk increased.

Answer 7

the first question : Iw
the second : in order to get the wheel to rotate you need to apply torque on it

Answer 8

is this the same question though ? the answers talk about disk but the question is about a wheel ?

Answer 9

sorry open study has been acting up on my computer. the options for the second question are:
It is a vector that points in the direction the bike would travel.

It is a vector that points along the axis of rotation perpendicular to the wheel.

It is a vector pointing radially outward from the center to the edge of the wheel.

It is a scalar.

Answer 10

It is a vector that points along the axis of rotation perpendicular to the wheel.

Answer 11

Consider a solid cylindrical disk rotating on an axis through its center. If the angular momentum of the disk increases, what can you conclude?

The net torque acting on the wheel was zero.

There was net torque acting on the disk.

The angular velocity remained unchanged.

The moment of inertia of the disk increased.

Answer 12

There was net torque acting on the disk.

Answer 13

so let me ask you a question. why this is the answer and not
"The moment of inertia of the disk increased."
as we said the angular momentum is Iw
so if I increases the angular momentum increase as well

Answer 14

i want to see that you understand

Answer 15

oh okay.

Answer 16

Which of the following is a statement of the law of conservation of angular momentum?

The angular momentum is the moment of inertia times the rate of rotation.

Objects at rest remain at rest, and objects in motion continue moving in the same straight line.

If the net force on an object is zero, the object has zero acceleration.

If the net torque on a system is zero, the angular momentum of the system does not change.

Answer 17

If the net torque on a system is zero, the angular momentum of the system does not change.

Answer 18

and you didnt answer yet

Answer 19

answer?

Answer 20

so let me ask you a question. why this is the answer and not
"The moment of inertia of the disk increased."
as we said the angular momentum is Iw
so if I increases the angular momentum increase as well

Answer 21

hmmm

Answer 22

so,
as we saw in the last question, If the net torque on a system is zero, the angular momentum of the system does not change.

our angular momentum is Iw

they say that the angular momentum of the disk increase.
but if there is no net torque then Iw have to be constant.
so if I goes up then w will go down! but the angular momentum remain the same!

Answer 23

ok

Answer 24

Which statement explains why a bicycle is stable when a rider pedals quickly?

The angular momentum vector resists directional change.

Applying a torque does not change the angular velocity of the wheel.

A rotating object acts like a magnet in seeking to point north.

When one object exerts a net torque on another, the second object exerts net torque on the first.