The discussion revolves around a scenario involving a pendulum that releases a bob, which subsequently pushes a box. The objective is to determine the coefficient of friction between the box and the surface it moves on, utilizing various measurements and equations related to energy and momentum.
Participants are actively engaging with the problem, providing calculations and questioning the validity of their approaches. Some guidance has been offered regarding the use of energy equations and the relationship between forces. There is a recognition of the need to clarify assumptions about the collision type and the materials involved.
There is a mention of potential confusion regarding the forum category for the question, indicating a need for clarity on posting guidelines. Additionally, participants highlight the importance of ensuring measurements are in the correct units.
N=NormalComeback City said:Is "N" representing normal force? If so, you cannot say it is equal to "W" (which I believe is Work(?)). Simple dimensional analysis doesn't allow this.
My mistake. I thought W was representing Work in your equation.MagnificentLiver said:N=Normal
W= Weight
U= Work
We have the weight of the box (W) pushing down on the surface and the normal reaction for pushing up (N) . Will assume up is positive.
ΣFy=0
N-W=0
N=W
W=mg
I believe this is a lab, not an abstract problem. Complications need to be considered, especially since the experimenters may have taken insufficient note of exactly what happened.Comeback City said:don't think the author of this problem
That's a major assumption.MagnificentLiver said:If we assume the bob came to rest as it hit the box
I agree it is a major assumption, but without actually seeing the lab we are unsure of the complete reaction between the two objects. I was just trying to use a broad approach to show how μ would be found if the pendulum reacted in that situation.haruspex said:I believe this is a lab, not an abstract problem. Complications need to be considered, especially since the experimenters may have taken insufficient note of exactly what happened.
That's a major assumption.
How about considering the various extremes and getting the range of possible coefficients?
Good point. Your idea of a contraption preventing further collisions was a good one in that case.haruspex said:I believe this is a lab, not an abstract problem. Complications need to be considered, especially since the experimenters may have taken insufficient note of exactly what happened.