7 thoughts on “Homework #10”

1. simms April 19, 2009 at 9:43 pm

   For the written homework – are we assuming that the ramp is a frictionless surface? or do we need to consider thermal energy?
2. simms April 19, 2009 at 10:04 pm

   forget the second part of my previous question! but new question: for part b: does “the force” mean the net force of the system (taking weight and normal force into account) or does it mean only the force of the push (10N)?

   thanks!
3. physics131-willocq Post authorApril 20, 2009 at 9:46 am

   The force to consider is indeed the 10 N force exerted by the push. To calculate the work done by that force you only need to know the magnitude of the force along the direction of motion of the box.
4. sarestad April 20, 2009 at 6:30 pm

   Is the magnitude of the force equal to F = ma?

   If so, is it added to the force exerted on the ramp or subtracted?
5. physics131-willocq Post authorApril 20, 2009 at 6:35 pm

   You do not need to know anything other than the fact that the force is 10 N. Compute the work using that.
6. rdetroy April 21, 2009 at 2:35 pm

   When calculating the net force, do we need to take into account the x-component of weight or can we simply use 10 N in the equation for work?
7. physics131-willocq Post authorApril 21, 2009 at 2:44 pm

   Just the 10 N since we are interested only in the work done by that force alone.