Thursday

December 18, 2014

December 18, 2014

Posted by **Alexis** on Sunday, October 14, 2007 at 6:25pm.

For Further Reading

physics repost - Alexis, Sunday, October 14, 2007 at 6:07pm

so it should be a 52000kg train slows from 25 m/s to 14m/s in 5.0 s. Calculate the work done on the train.

so I found the displacement by using

displacement= 1/2 (v1+v2) (delta t)

and got 97.5

and then I found the force which is F=mg

and got 510120N, then took that force and did W=Fd

and got 49736700J

my textbook says 1.1x10^7J? How is that right? I think I am right?

physics repost - Alexis, Sunday, October 14, 2007 at 6:17pm

I tried to get the answer using the kinetic energy formula, and it works (for the answer of 1.1x10^7), but the only problem is, the homework is for the pages before the kinetic energy, so I would like to know how to figure out the answer without the kinetic energy formula. Thank you for helping me!

- Just a repost, in case the old isnt seen -
**Alexis**, Sunday, October 14, 2007 at 6:31pmHAHA I just got the answer!!!! You don't use F=mg it should be ma!!! Thanks anyways!!

**Answer this Question**

**Related Questions**

physics repost - sorry! I never noticed..the mass should be 52000kg sorry about ...

english - Homework Help Forum: brain teaser help Current Questions | Post a New ...

english - sorry i havent really used this site and im not sure how to repost my ...

About Posting - sorry for repost ~C

algebra 117 - repost sorry about that (k^1/8)^-4 oer(k^7)^1/2

Physical Science - if you tear a piece of material in haft, how is the density ...

Hottie - If you want to be banned from this site, keep it up. sorry about my ...

chem -repost for bobpursley - i don't know how to solve this. looked through all...

WHY? - WHy are my questions being deleted? plz help me..i didnt mean to be rude...

Physics-repost, sorry, I still don't understand :( - A forearm with a mass of 1....