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Energy question

  • Thread starter Luke1121
  • Start date
  • #1
14
0
I've got an answer to a question but i'm not sure if it's correct as i dont have the answers.

A roller coaster train is propelled at 57m/s and towards a vertical part of track which has a height of 139m, what is the velocity of the roller coaster train when it reaches the top of the tower?
I got that:
Ek=Ep so
1/2mv^2=mgh so m's cancel so 1/2v^2=gh
so in relation to the questiom
1/2(57)^2=1/2v^2 + gh (because energy is conserved so potential energy must be added)
Then
1624.5=1/2v^2 + 1363.6
290.9=1/2v^2
etc, etc and ended up with 22.84 m/s but i've no idea if this is correct as i've never come across a question like this before. does this seem right? Thanks
 

Answers and Replies

  • #2
1,198
5
It is correct.
 
  • #3
58
0
I think it's right, I am getting the same answer. But, I did it using a different method:
v2=u2+2as

u=57 m/s
a=-g
s=139 m
(we have to find v)
 
  • #4
1,033
1
I got the same answer as you.
 

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