The discussion centers on calculating the coefficient of friction for a box pushed by a pendulum bob after a collision. Key measurements include the bob's mass (125 grams), the box's mass (267.3 grams), the pendulum length (27 cm), the distance moved by the box (3.2 cm), and the angle of release (30 degrees). The conservation of momentum and energy equations are utilized to derive the initial velocity of the box and the normal force, leading to the calculation of frictional force. The final coefficient of friction is estimated to be approximately 0.271 based on experimental data.
PREREQUISITESStudents in physics, particularly those studying mechanics, as well as educators and anyone interested in understanding the dynamics of collisions and friction in practical scenarios.
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.