Calculating Angular Speed with a Running Person on a Rotating Disk?

AI Thread Summary
To calculate the angular speed of a rotating disk with a person running on it, the principle of conservation of angular momentum is key. Initially, the disk is stationary, so its angular momentum is zero. As the person runs with a tangential speed of 2.20 m/s, their angular momentum can be calculated using the formula L = m * v * r, where m is the person's mass, v is their tangential speed, and r is their distance from the axis. The disk will start rotating in the opposite direction to conserve angular momentum, and the resulting angular speed can be found by equating the angular momentum of the person to that of the disk. This approach effectively combines the concepts of linear and angular motion to solve the problem.
mparsons06
Messages
60
Reaction score
0

Homework Statement



A flat uniform circular disk (radius = 2.18 m, mass = 1.22E+2 kg) is initially stationary. The disk is free to rotate in the horizontal plane about a frictionless axis perpendicular to the center of the disk. A 42.9 kg person, standing 1.29 m from the axis, begins to run on the disk in a circular path and has a tangential speed of 2.20 m/s relative to the ground. Calculate the resulting angular speed of the disk (in rad/s).

I don't even know where to start. Please help?!
 
Physics news on Phys.org
One hint: angular momentum.
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Determining $L_{o}$: Finding Angular Momentum of System
Replies
45
Views
4K
Angular speed calculation after an inelastic collision
Replies
20
Views
3K
Rotational Momentum: Calculating Angular Speed After Cockroach Stops
Replies
2
Views
2K
Calculating Final Angular Speed of a Rotating Disk with a Horizontal Axis
Replies
8
Views
3K
Angular Momentum Problem: Mouse walking on a rotating turntable
Replies
5
Views
1K
Time required for disk to reach angular speed?
Replies
11
Views
2K
Conservation of Energy and Angular Momentum in a Rotating Train-Disk System
Replies
30
Views
3K
Perfectly inelastic collision of two moving and rotating disks
Replies
9
Views
2K
Masses Moving Radially on a Rotating Disk
Replies
8
Views
2K
Calculating Angular Velocity of Disk w/ Angular Momentum
Replies
1
Views
1K

Hot Threads

Recent Insights

Back
Top