Vriti Edustore
Home »
Ask & Discuss
»
Physics
« Back to Discussion
Mechanics
1 Apr 2010 00:34:58 IST
59 People liked this
52
4316
When we walk the work done by friction is negative or positive....?
Engineering Entrance
,
Medical Entrance
,
AIPMT
,
JEE Main
,
AIIMS
,
JEE Advanced
,
Physics
,
Mechanics
,
Kinematics
,
NewtonsLawsCirMotion
,
Work Power Energy collisions
,
Rotation
,
Gravitation
,
Simple Harmonic Motion
,
Fluid Mechanics
,
Materials Wave Sound
,
Super Position
,
units dimensions
,
com momentum
,
shm
,
wave sound
When we walk the work done by friction is negative or positive....?
Comments (52)
7 Apr 2010 08:40:24 IST
Like
0 people liked this
What are you trying to say? Read my answers once more please, I am making a similar point, I am not considering any change in the direction of the frictional force. And this does not answer the question here. And the doubt was never mine, I was just trying to clear it for the one who asked.
5 May 2013 14:22:15 IST
Like
0 people liked this
OBSERVATION: you will observe that the ink will flow (blot) to forward side of sole much larger and a very little backward. so, we can conclude that upper layer of in contact with ink is a rest while that with ground is experiencing a viscous drag due to friction in FORWARD (because most of the ink will flow forward)....so, the ground friction will act forward.
5 May 2013 14:33:41 IST
Like
0 people liked this
now, those who say that the point of contact is at rest... its just ideal, in real, you can't walk properly, if the point of contact will be at rest as you will get jerk in your motion....................in real world, there occurs a little displacement of point of contact......... the point of contact experience max displacement on slippery surface,,,, and minimum, but not zero.... ..... i , better give you example.... you are walking on hard soil, in usuall manner , suddenly a swampy, wet soil(the crust is very weak) ...you cant walk on it with your slipper and you would require to take it on your hand.... but in this case too, where the earth crust is slightly smooth, or water is not absorbed properly,, you will experience sudden slipping,,, and you are required to take the smaller steps there to ensure minimum displacement of point of contact.................hope you all understood...
Free Sign Up!
Preparing for JEE?
Kickstart your preparation with new improved study material - Books & Online Test Series for JEE 2014/ 2015
@ INR 4,950/-
For Quick Info
Find Posts by Topics
Physics
Topics
10271
20997
3867
2300
8075
2968
2790
Mathematics
Chemistry
Biology
Institutes
Parents Corner
Board
Fun Zone
|
Vertical Limit 
Top Contributors
All Time This Month Last Week | 1. |
|
Bipin Dubey
|
| 2. |
|
Himanshu
|
| 3. |
|
Hari Shankar
|
| 4. |
|
edison
|
| 5. |
|
Sagar Saxena
|
| 6. |
|
Yagyadutt Mishr..
|
| 35,229,755 Engineering Questions Attempted |
6,69,530 Visitors Monthly |
79 Engg. Exam Covered |
1624 Students Currently Online |
Connect with Us  |
 |
Vriti Communities
Privacy Policy © Vriti 2011
@Optimus
Friction i a non conservative force and it is path dependent. So then we walk.... How do you walk... push the ground behind and the ground pushes you forward... now the friction is between your feet and ground. now when you push the ground the friction should have a direction in the direction opposite to that of the relative motion of your feet else you would fall down. So friction acts in the forward direction. But when the ground pushed you back.... the point of application of force loses contact so the change in direction of friction doesn't come into play. Hope fully you must have got it....