alright, the formula is dU = Q - W. Work is done ON the system so W is going to be negative (right?). [W = -220J]. dU is -500J, because it initially lost that 500J so if you plug in ... -500J = Q -(-220). solving for Q would therefore yield Q = -720J. Am I correct?
oh yes, I see now. The one site that had the -720J answer notated it as
3. DU = Q – W or Q = DU + W = –500J – 220 J = –720 J
which would therefore yield that answer, I think... wow now I'm confusing myself, so it is -280J?
alright, so I'm reviewing for a test I have on monday, and I was given a study guide which we must answer in order to get ready for the test. Now I just breeze through this stuff like its nothing, but I've found on discrepency. I even looked up the question online and i got 2 completely...
Oh believe me, I understand...AP Phys is by far my favorite class outta my 4 years of HS. And I finished Calc II last year, so I'm not exactly amateur with the mathematical part, but as you said, putting it all together is where I'm falling here. But If you could possibly give it a shot at...
Yea thanks a lot Diane, you've been a great help, I'll see what I can manage, but - I'm a bit confused as to what these "equations" will look like. We've only just touched on this friction chapter, and its all somewhat new to me.
anyone got any ideas?...I messed around with the site program thing they have using the aforementioned values, and through trial and error, managed to get 20.3 degrees to = 0 accelleration...that might be right, might be wrong, but if anyone has any input, feel free to comment
Ok..heres the question verbatim, I think I just realized something, a will be 0, according to the question
A block weighing 130 N is on an incline. It is held back by a weight of 45 N hanging from a chord that passes over a frictionless pulley and is attached to a block as shown below [seen...
Yes it does a bit, but I think I managed to solve for the accelleration. Correct me if I'm wrong.
(45 - (.620)(130))/ (4.591 + 13.26)...and this yielded an accelleration of 2 m/s^2. Would that enable me to solve my problem with this information?
alright, so I was searching for a physics problem, and i came upon this http://www.fearofphysics.com/Probs/mech041.html .This is exactly the problem I was looking for, except, rather than you providing the angle, you are provided with the coeffifient of friction (.620) , as well as the 2 weights...