What is the Velocity of the Combined Freight Cars in a Collision?

  • Thread starter Thread starter jazzysoshort
  • Start date Start date
  • Tags Tags
    Momentum Velocity
AI Thread Summary
In a freight yard scenario, an empty freight car moving at 10 m/s collides with a stationary loaded car, resulting in both cars coupling together. The empty car has a mass of 3,000 kg, while the loaded car weighs 15,000 kg (3,000 kg plus 12,000 kg of cargo). The momentum of the empty car is calculated as 30,000 kg·m/s, and the total momentum after the collision is 150,000 kg·m/s. The combined mass of the two cars is 18,000 kg, leading to a calculated velocity of 180 m/s, which is incorrect. The focus of the discussion is on applying momentum principles to solve for the post-collision speed of the coupled freight cars.
jazzysoshort
Messages
4
Reaction score
0

Homework Statement


In a freight yard a train is being put together from freight cars. An empty freight car, coasting at 10m/s, strikes a loaded car that is stationary, and the cars couple together. Each of the cars has a mass of 3000 kg when empty, and the loaded car contains 12,000 kg of canned soda. With what speed does the combination of the two cars start to move?


Homework Equations


p=mv (f)(change in time)=p



The Attempt at a Solution


calculated p for empty car p=(10)(3000) p=30,000
calculated the full momentum p=(10)(15000) p=150,000
totaled the masses to find the velocity 180,000=18,000v v=180 m/s
 
Physics news on Phys.org
nvm.
 
No i didn't find inertia, but the whole worksheet is dealing with momentum and impulse.
 

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

Momentum Kleppner Classical Mechanics Freight Car and Hopper
Replies
10
Views
3K
What Is the Speed of Five Coupled Freight Cars After a Collision?
Replies
4
Views
2K
Momentum in a perfectly inelastic collision
Replies
6
Views
2K
How Does Sand Transfer Affect the Speed of a Freight Car?
Replies
2
Views
4K
Estimate the initial velocity of the cars after the collision
Replies
29
Views
3K
A train dragging coal while more coal is added into it....
Replies
3
Views
2K
What Is the Speed of a Freight Car When All the Sand Is Gone?
Replies
32
Views
8K
What Was the Initial Speed of the Freight Car?
Replies
11
Views
3K
Momentum, collision of two cars problem
Replies
5
Views
6K
Conservation of Momentum with Collisions
Replies
1
Views
1K

Hot Threads

Recent Insights

Back
Top