Forces involving static friction

AI Thread Summary
The problem involves determining the shortest distance a railroad flatcar can stop without crates sliding, given a coefficient of static friction of 0.25 and an initial speed of 48 km/h. To solve it, one must first calculate the maximum acceleration using the static friction force, which is determined by the equation f = μF. The next step involves applying kinematics to relate the initial speed to the stopping distance. Understanding the relationship between force, mass, and acceleration is crucial for finding the solution. The key is to find the maximum acceleration that static friction can provide before the crates begin to slide.
america8371
Messages
4
Reaction score
0

Homework Statement


The floor of a railroad flatcar is loaded with loose crates having a coefficient of static friction of 0.25 with the floor. If the train is initially moving at a speed of 48 km/h, in how short a distance can the train be stopped at constant acceleration without causing the crates to slide over the floor?


Homework Equations


f = \mu F
F = m a


The Attempt at a Solution


This is my first post so I hope did it correctly. Ok so I first tried to draw a force diagram but this is the first problem that has included a speed into it. I know its probably something simple that I'm just not thinking of but I'm having trouble seeing how I can relate speed to any of the equations in this section. Thanks in advance.
 
Physics news on Phys.org
The speed will come in when you apply kinematics to find the shortest distance. But first you must find the maximum acceleration.

Hint: What force accelerates the boxes? What's the maximum value of acceleration that that force can produce?
 

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 '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 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

Force of the wall against the ladder is from static friction?
Replies
6
Views
3K
Static friction coefficient for a crate in the back of a truck
Replies
6
Views
2K
Static equilibrium | Uniform sphere on incline | Determining friction
Replies
43
Views
2K
Is it friction or tension acting on the person hanging on a rope?
Replies
4
Views
995
Friction problem of a block sandwiched between 2 surfaces
Replies
6
Views
1K
Frictional Forces and Two dimensional constant acceleration problem
Replies
2
Views
2K
Banked Curve-Determine smallest static coefficient of friction
Replies
9
Views
4K
How can I determine the instant the block overcomes static friction?
2
Replies
61
Views
3K
Force, Friction, Feel like I am not given sufficient info
Replies
3
Views
1K
Rolling without slipping problem
Replies
42
Views
3K

Hot Threads

Recent Insights

Back
Top