Posted by Amelia on Thursday, May 10, 2012 at 11:22am.
In the 1950s, an experimental train that had a mass of 3.30 104 kg was powered across level track by a jet engine that produced a thrust of 4.90 105 N for a distance of 600 m.
(a) Find the work done on the train.
1 J
(b) Find the change in kinetic energy.
2 J
(c) Find the final kinetic energy of the train if it started from rest.
3 J
(d) Find the final speed of the train if there was no friction.
4 m/s

Homework dumping  Writeacher, Thursday, May 10, 2012 at 11:29am
Your umpteen posts have been removed.
Once you write up YOUR THOUGHTS, please repost, and someone here will be happy to comment. 
physics  Elena, Thursday, May 10, 2012 at 4:22pm
1) Work = force • distance
Work = F•s = 4.9•105•600 =2.94•10^8 J.
2) work done = energy gained
Kinetic energy gained = 2.94•10^8 J It had 0 KÓ to start, so this is its change in KE.
3) This is also the final KE of the train.
4) KE = m•v²/2.
2.94•10^8 = 0.5•3.3•10^4• v².
V = sqrt (2.94•10^8/0.5•3.3•10^4) = 133.5 m/s