What is the Angular Velocity of a Sliding Beam and Man System?

AI Thread Summary
The discussion focuses on calculating the center of mass velocity and angular velocity of a system consisting of a sliding beam and a man who grabs it. For part (a), the center of mass velocity is determined to be 7.02 m/s after applying conservation of momentum, leading to a post-collision speed of 14.03 m/s. In part (b), the angular velocity is calculated using the relationship between linear velocity and radius, resulting in an angular velocity of 5.2 rad/s. Participants seek confirmation on the correctness of these calculations and the methodology used. The approach appears sound based on the provided equations and results.
BIOPSYCH
Messages
11
Reaction score
0

Homework Statement



A 230 kg beam 2.7 m in length slides broadside down the ice with a speed of 18 m/s. A 65 kg man at rest grabs one end as it goes past and hangs on as both he and the beam go spinning down the ice. Assume frictionless motion.

(a) How fast does the center of mass of the system move after the collision?

(b) With what angular velocity does the system rotate about its center of mass?



Homework Equations



For part (a)

(mass before)(linear velocity) = (mass after)(linear velocity after)

velocity at CM: 1/2(linear velocity after)

For part (b):

v = \omegar

The Attempt at a Solution



Part (a):

230(18) = (230+65)v

v= 14.03 m/s

v at CM: 1/2(v)

v at CM: 7.02 m/s

Part (b):

v=\omegar

14.03 = 2.7 \omega

\omega= 5.2 rad/s

Is this correct? Is there something I am missing?
 
Physics news on Phys.org
Does anyone know if this approach is correct?
 
Does anyone know if this is correct?
 
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...
Thread 'Calculation of Tensile Forces in Piston-Type Water-Lifting Devices at Elevated Locations'
Figure 1 Overall Structure Diagram Figure 2: Top view of the piston when it is cylindrical A circular opening is created at a height of 5 meters above the water surface. Inside this opening is a sleeve-type piston with a cross-sectional area of 1 square meter. The piston is pulled to the right at a constant speed. The pulling force is(Figure 2): F = ρshg = 1000 × 1 × 5 × 10 = 50,000 N. Figure 3: Modifying the structure to incorporate a fixed internal piston When I modify the piston...
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...
Back
Top