Answer:
The second classmate is right.
Explanation:
The height of first summit provides the potential energy it will use to climb the following ones.
Ep = m * g * h
Where
m: mass
g: acceleration of gravity
h: height
When the train goes downwards the potential energy is converted into kinetic energy (manifested as speed) and when it climbs it consumes its kinetical energy. As long as no summit is taller than the first the train should have enough energy to climb them.
Also it must be noted that friction also consumes energy, and if the track is too lomg all the energy might be consumed by it.
Answer:
I think it is( More expensive than immature technologies) I took engineering class and this question is still quite tricky.
Explanation:
Answer:
The conversion in the real reactor is = 88%
Explanation:
conversion = 98% = 0.98
process rate = 0.03 m^3/s
length of reactor = 3 m
cross sectional area of reactor = 25 dm^2
pulse tracer test results on the reactor :
mean residence time ( tm) = 10 s and variance (∝2) = 65 s^2
note: space time (t) =
t =
Vo = flow metric flow rate , L = length of reactor , A = cross sectional area of the reactor
therefore (t) =
= 25 s
since the reaction is in first order
X = 1 - 
= 1 - X
kt = In 
k = In
/ t
X = 98% = 0.98 (conversion in PFR ) insert the value into the above equation then
K = 0.156 
Calculating Da for a closed vessel
; Da = tk
= 25 * 0.156 = 3.9
calculate Peclet number Per using this equation
0.65 = 
therefore

solving the Non-linear equation above( Per = 1.5 )
Attached is the Remaining part of the solution