- #1
SpY]
- 65
- 0
So my lecturer asked a physics audience (final year and postgrad) this question and no one got it right (at first):
Consider a block pushed back and forth on a flat table. Draw a graph of the applied force vs. friction. Take a minute to figure this one out yourself, then click this link for his solution.
http://i55.tinypic.com/2zpl53s.jpg
Trouble I'm having is interpreting the two lines, because it implies on the x-intercept that you will have a positive acceleration when there is no applied force, so the resultant force must be friction - which cannot exist without an applied force!
Consider a block pushed back and forth on a flat table. Draw a graph of the applied force vs. friction. Take a minute to figure this one out yourself, then click this link for his solution.
http://i55.tinypic.com/2zpl53s.jpg
Trouble I'm having is interpreting the two lines, because it implies on the x-intercept that you will have a positive acceleration when there is no applied force, so the resultant force must be friction - which cannot exist without an applied force!