Question

This set of questions uses an interesting formula. A torque applied for a certain time causes a change in angular momentum.
Torque * (delta t) = delta L

Lindsey is on the merry-go-round again. Her mass is 33kg . The merry-go-round has a mass of 78kg and a radius of 2.20m. Lindsey is standing 0.150m from the center and has an initial angular velocity of 3.45 rad/sec. Her older brother Mike applies a force of 200 N tangent to the outer edge for causing the merry-go-round to spin faster. What was the initial angular momentum before Mike pushed?

I'm lost in the information...what steps do I need to take, and how does that formula factor in?

Answer 1

torque = dL/dt = rate of change of angular momentum

What else is new?

I is moment of inertia of merry-go-round with Lindsey on it.

omega = 3.45

L = I omega = 3.45 I
that is the initial angular momentum

Torque = I d omega/dt
or
200 * 2.20 = I d omega/dt
if you know I you can get d/dt (omega)

Answer 2

Thank you so much!!