Not sure how to start this one any hints would be most helpful

  • Thread starter Thread starter dstahn
  • Start date Start date
AI Thread Summary
The discussion revolves around a broken cable in a 2017-kg elevator that descends at a constant speed of 1.64 m/s, indicating that the frictional force from the safety braking system balances the gravitational force. Participants are exploring the relationship between the mechanical energy being converted to thermal energy and the rate of work done by the braking system. The key equation mentioned is the rate of doing work, calculated as the product of the frictional force and the elevator's velocity. The conversation highlights the need to determine the frictional force to find the energy conversion rate. Understanding these concepts is essential for solving the problem effectively.
dstahn
Messages
7
Reaction score
0
The cable of a 2017-kg elevator has broken, and the elevator is moving downward at a steady speed of 1.64 m/s. A safety braking system that works on friction prevents the downward speed from increasing. At what rate is the braking system converting mechanical energy to thermal energy?

Im not real sure what equations to use. Sorry I'm not very helpful. This one just kinda stopped me in my tracks for some reason.
 
Physics news on Phys.org
Since elevator is falling with constant velocity, the frictional force must be equal to...?
Then rate of doing work = Fr*v.
Now what is relation between the mechanical energy and the thermal energy?
 

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

Work / Energy Elevator / Spring Problem
Replies
5
Views
4K
Question about springs and rotational/translational energy
Replies
4
Views
1K
Question: "A child on a sled (m=47.0 kg) slides down a long hill "
Replies
2
Views
6K
Cable car and counterweight forces problem. (Tension)
Replies
5
Views
11K
Energy dissipation when a lift stops
Replies
15
Views
2K
Finding the Speed of a Falling Elevator with a Spring and Frictional Force
Replies
15
Views
31K
Elevator Question (Rotation of rigid body and Energy)
Replies
3
Views
5K
Conservation of Energy Possibly
Replies
7
Views
2K
I'm stuck Not sure where to go. Help
Replies
5
Views
2K
Conservation of energy of an elevator
Replies
2
Views
5K

Hot Threads

Recent Insights

Back
Top