Calculating Force at Left Point of Support on Bridge

AI Thread Summary
To calculate the force at the left point of support on a bridge, it's essential to apply both the sum of forces and the sum of torques principles. The bridge, measuring 60 m and weighing 51,800 kg, supports a truck of 45,000 kg positioned 26 m from the left end. Identifying all forces acting on the bridge is crucial, as is selecting an appropriate pivot point for torque calculations. The discussion emphasizes the importance of correctly determining the axis for torque to arrive at the right answer. Proper analysis of forces and torques will yield the necessary calculations for the left support force.
kitty9035
Messages
17
Reaction score
0

Homework Statement


A bridge of length 60 m and mass 51800 kg is supported at each end. A truck of mass 45000 kg is located 26 m from the left end.


Homework Equations


What is the force on the bridge at the left point of support?


The Attempt at a Solution



I know your supposed to use the sum of the forces equals zero. Then the sum of the torques equal zero, but i can't get the right answer!:eek:
 
Physics news on Phys.org
the reason is because you are trying to set the sum of all forces equal to zero when you don't even know enough forces. Look at torques. Try my suggestion on the other problem.
 
kitty9035 said:
I know your supposed to use the sum of the forces equals zero. Then the sum of the torques equal zero, but i can't get the right answer!:eek:
First identify all the forces acting on the bridge. Then show us exactly how you calculated the torques. (What point did you use as your pivot point?)
 
Its all about the choice of axis. You have all you need if you choose the right point
 

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

Equilibrium of Forces and Torques on Sawhorses Supporting a Person on a Board
Replies
6
Views
2K
Torque Rigid Beam: Find Force Applied by Support 2
Replies
4
Views
2K
Find the angular acceleration of the bridge?
Replies
1
Views
3K
The force required to raise a bridge/lever to an angle?
Replies
7
Views
3K
Forces acting on a support point after the system is released
Replies
6
Views
1K
How Do Forces Distribute on a Board Supported at Two Points?
Replies
6
Views
2K
How to calculate the tension in a beam of a bridge?
Replies
29
Views
9K
Finding the Force Applied by a Support on a Falling Chain
Replies
2
Views
2K
Calculating Forces Acting on a 50m Bridge with Two Supports: A Torque Question
Replies
1
Views
2K
Calculating Forces and Torques in a Basic Equilibrium Problem
Replies
4
Views
2K

Hot Threads

Recent Insights

Back
Top