How far does the train travel before the engine is ....

AI Thread Summary
The discussion revolves around calculating the distance a model steam train travels before its engine reaches maximum force. The train's speed is defined by the equation v = 5t + 2t^2 - t^3, and the initial position is set to zero since it starts from rest. Participants express confusion about the relationship between maximum force and acceleration, questioning whether they should focus on displacement. The concept of maximum force is linked to the force required to initiate movement. Understanding the connection between force, acceleration, and displacement is crucial for solving the problem effectively.
siimplyabi
Messages
9
Reaction score
0

Homework Statement

.[/B]
A model steam train engine has a mass of 2.3 kg is powered by a sterno and white gas mixture that heats a small boiler. Once sufficient steam pressure is produced, the train is released from rest. The train travels along a straight and level track. At any time after release and before it comes to rest, the train’s speed can be expressed by v = 5t + 2t 2 − t 3 .

a) How far does the train travel before the engine is producing maximum force?

Homework Equations

The Attempt at a Solution


I've only been thinking on how i can approach this problem and I haven't had any luck. I've tried drawing Free body Diagrams and drawing forces but it's not helping and its because i don't really understand what they are asking for.

Am I looking for a displacement? Now i know the initial position is 0 since it was released from rest.
Now I am guessing max force is the force needed to get the train moving?
Please help.
 
Physics news on Phys.org
The v= 5t+2t^2-t^3
 
siimplyabi said:
Now i know the initial position is 0 since it was released from rest.

Released from rest means the initial velocity is zero.

Now I am guessing max force is the force needed to get the train moving?

When the force has its maximum value, what can you say about the acceleration?
 
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 '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