Lost in the Distance: Navigating Measurement

  • Thread starter Thread starter fcici7
  • Start date Start date
  • Tags Tags
    Lost Measurement
AI Thread Summary
The discussion highlights confusion regarding a problem statement that lacks clarity and essential details, such as specific temperature comparisons and the context for a camera and graph mentioned. Participants note that the expansion coefficients for two metals are referenced without prior explanation. There's also ambiguity about the train's mechanics, particularly regarding its speed and whether it is powered or has brakes engaged. A suggestion is made to assume the train rolls freely downhill to simplify calculations. The overall consensus emphasizes the importance of providing complete information for effective assistance.
fcici7
Messages
2
Reaction score
0
Homework Statement
The following information must be considered: the total mass of the cars and riders is 5225 kg. The train leaves the station at 4.5 m/s and it reaches a speed of 8.0 m/s at the top of the first hill. It takes 16.0 seconds to reach the top. The first hill (on the upwards and the downward side) is angled at 38o. The specific heat capacity of brass and the coefficient of linear expansion of steel are 376 J/kgoC and 12 x 10-6 oC-1, respectively. On the day of analysis, the air temperature is 30.oC. We will also assume that the station track is at ground level. In order to determine the length of track, use a piece of string and the vertical scale outlined on the graph.
With what speed would it reach the bottom of the first hill?
How long will it take for the camera to reach the ground?
Relevant Equations
Any kinematic formulas, Froce formulas and [work, power and energy formulas]
specific formulas were not given with this question.
I tried finding the distance but I later on got confused.
 
Physics news on Phys.org
Are you a bot?
 
no? I am sorry if i sounded like a bot lol, i was just trying to write as fast as i can
 
fcici7 said:
no? I am sorry if i sounded like a bot lol, i was just trying to write as fast as i can
The reason for the query was the very disjointed nature of the problem statement.
It specifies expansion coefficients for two metals, but no mention of these in the set up.
One temperature is given, but no other temperature to compare with.
There's a question about a camera, but no prior mention of such.
There's mention of a graph, but it does not instruct you to draw one and you have not attached one.
The train gets faster going up the hill so must be powered by an engine, but we are not told whether it is still engaged, or any brakes applied, on the downhill.

I suggest you assume the train rolls freely downhill. You know its speed at the top and the angle it comes down at. What else do you need to find the speed at the bottom?
 
  • Like
Likes Delta2 and berkeman
Considering the information given, one might just as well ask for the name of the train engineer.
fcici7 said:
. . . i was just trying to write as fast as i can
What's your hurry? It seems that writing fast caused you to skip some of the information that you were given. We cannot help you unless you post all the information that you have.
 
  • Like
Likes Delta2 and berkeman
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...
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...
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...
Back
Top