citypigeon
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Homework Statement
In the 1950s, an experimental train that had a mass of 2.50 x 10^4 kg was powered across the level track by a jet engine that produced a thrust of 5.00 x 10^5N for a distance of 509m.
a)Find the work done on the train
b)Find the change in kinetic energy
c)Find the final kinetic energy of the train if it started from rest
d)Find the final speed of the train if there were no friction.
Homework Equations
The Attempt at a Solution
a)
W=fd
W= (5.00 x10^5N)(509m) = 2.545 x 10^8
b)
I'd typically find the change in KE when I have differences in velocity b/c of the equation KE=(1/2)mv^2, but I don't have v in this equation and I don't know how to find it when I don't have time (t).
I know KE changes when there is change in height, but the train runs on a level track, does that mean there is none?
Then in my review book it says W= KE initial - KE final = change in KE
Does that mean the work I found done on the train is the same as the change in KE involved? I don't know...
c)
I used v(f)^2 = v(i)^2 = 2ad
v(f)^2= 2(9.8)(509)
=99.88
d)
I really don't know how to approach this one...