![]() |
| If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|||||||
| Tags: energy, problem, work |
|
|
Thread Tools | Display Modes |
|
#1
|
|||
|
|||
|
Greetings to all. I hope that someone here will be able to shed some light
on my questions. For those of you who have the book, Serway & Faughn, College Physics 5th Edition, I am referring to question 5.39. "A skier starts from rest at the top of a hill that is inclined at 10.5 degrees with the horizontal. The hillside is 200m long, and the coefficient of friction between snow and skis is 0.0750. At the bottom of the hill, the snow is level and the coefficient of friction is unchanged. How far does the skier move along the horizontal portion of the snow before coming to rest?" Possible solution: The Fn of skier is mgcos10.5 while on hill and Fn of skier is mg on horizontal portion. Using F * s = Wnc = (KEf + PEf) - (KEi + PEi) and defining the bottom of hill as zero level for potential energy, I used F * s = (0.0750)(mgcos10.5)(200) = (1/2)m(v)^2 + 0 - 0 - mgh (h = 200sin10.5). I determined v = 19.02 m/s. Using F * s = Wnc = (KEf + PEf) - (KEi + PEi), I used F * s = (0.0750)(mg)(s) = 0 + 0 - (1/2)(m)(19.02)^2 + 0. s = 246.1m. The answer in the back of the book is s = 289m. Did I do the problem wrong? If so, can I solve it this way? Thanks, Will |
| Ads |
| Thread Tools | |
| Display Modes | |
|
|
Similar Threads
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| Work, gravity, potential energy | Eli Luong | Physics - General Discussion | 6 | January 17th 06 02:22 PM |
| Question about work and energy transfer | cool_cat | Physics - General Discussion | 13 | July 4th 05 05:05 PM |
| Work-Energy Question | JamesLan | Physics - General Discussion | 7 | March 21st 05 02:39 AM |
| Work and Energy Problem | Will | Physics - General Discussion | 5 | September 1st 04 06:01 AM |
| Mass, energy, work & power | Donald G. Shead | Physics - General Discussion | 12 | August 20th 03 06:23 AM |