Help with decelleration, acceleration and time

  • Thread starter Thread starter djszkoda
  • Start date Start date
  • Tags Tags
    Acceleration Time
AI Thread Summary
To solve the problem of deceleration and acceleration between two trains, use the formula v² - u² = 2as, where u is the initial velocity, v is the final velocity, s is displacement, and a is acceleration. This equation allows for the calculation of displacement (s) and subsequently time (t). The scenario involves one train slowing down and stopping while the other continues at cruising speed, creating a time separation at the next station. Understanding the relationship between acceleration, deceleration, and time is crucial for determining the time gap between the two trains. Accurate calculations will provide the necessary time separation as they pass through the station.
djszkoda
Messages
1
Reaction score
0
delete please.
 
Last edited:
Physics news on Phys.org
Hi, welcome to PF.

You need to use v^{2}-u^{2}=2as where u is the initial velocity, v the final, s is the displacement and a is the acceleration. From this you can find s and then find t.
 
You have everything you need.

Imagine two trains running together on parallel tracks. One slows down, stops for a while and then accelerates back to cruising speed. The other one is now a good way ahead. What you have to find is the time separation between these two trains as they pass through the next station without stopping.
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

Relating acceleration to distance and time
Replies
5
Views
3K
Why would this be accelerating positively?
Replies
6
Views
963
Kinematics: Acceleration of a figure skater changing direction
Replies
16
Views
1K
Zero velocity for a time interval, what about acceleration?
Replies
7
Views
2K
Terminal velocity and acceleration
Replies
7
Views
909
Kinematics, is this a poorly worded question?
Replies
7
Views
836
Solving for Time Given Acceleration & Initial Velocity
Replies
3
Views
1K
Verifying the acceleration of gravity in our lab (help with error please)
Replies
7
Views
2K
Does a linearly time varying B create changing E?
Replies
4
Views
2K
Average acceleration of an arrow by a bow
Replies
2
Views
3K

Hot Threads

Recent Insights

Back
Top