Find Maximum mass with the principles of torque and rotational equilibrium

AI Thread Summary
To determine the maximum mass a man can have on a 3m beam without snapping a supporting cable, the principles of torque and rotational equilibrium must be applied. The beam's weight, converted to Newtons, is 245N, and the cable can support a maximum force of 1800N at a 30-degree angle. The initial approach of simply subtracting the beam's weight from the cable's maximum force was incorrect due to neglecting the angle's effect on the force components. The correct calculation involves summing the forces in the Y direction, considering the angle of the cable relative to the beam. The maximum mass that can be supported is 79.3 kilograms.
Leanna.Agahi
Messages
1
Reaction score
0
I need help with this physics problem! Please help I'm completely stuck.

A beam 3m long is free to pivot up and down about the end attached to a wall. The mass of the beam is 25 kg and the cable supporting the beam can support a maximum force of 1800 N. What is the maximum mass that a man standing on the end can have before he snaps the cable. The angle of elevation between the cable and the beam is 30 degrees.
?
I tried converting the 25 kg to Newtons, therefore getting me 245N and subtracting that from the 1800 (which I thought would be the easy way) and then dividing by 9.8 to get the mass in kg, but that ended up being incorrect.

The correct asnwer is 79.3 Kilograms, but I would enjoy to know how to get to that conclusion.
 
Physics news on Phys.org
You are almost correct except one thing, you forgot the angle of the cable relative to the beam.

redo your equation by summing the forces in the Y direction (1800N is not in the Y direction)
 
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanged mass'

Thread 'A cylinder connected to a hanged 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

Torque and rotational equilibrium question
Replies
6
Views
4K
Equilibrium of Forces and Torques on Sawhorses Supporting a Person on a Board
Replies
6
Views
2K
Torque and Rotational Equilibrium with a slanted Rod/Cable
Replies
7
Views
3K
Question about static equilibrium
Replies
18
Views
2K
Solving Equilibrium w/ Plank & Forces | Physics Problem
Replies
7
Views
4K
Sum of torques, equilibrium problem
Replies
3
Views
2K
Question about springs and rotational/translational energy
Replies
4
Views
1K
Torques on a vertical wheel due to 3 masses spaced along the wheel rim
Replies
13
Views
3K
Find the mass M so that the net torque is zero
Replies
6
Views
2K
Torque seesaw problem- rotational equilibrium
Replies
7
Views
17K

Hot Threads

Recent Insights

Back
Top