The discussion revolves around the impulse-momentum method in linear motion, specifically addressing the application of the formula FT = mVf - mVi in various scenarios. Participants explore the implications of sign conventions in force calculations and the treatment of objects in motion, particularly when friction is involved.
The conversation is ongoing, with participants providing insights into the importance of sign conventions and the necessity of treating objects separately when friction is a factor. Some guidance has been offered regarding the interpretation of results and the conditions under which impulse momentum can be applied.
Participants note that the problem does not specify the direction of motion, leading to ambiguity in sign conventions. The discussion also highlights the need for clarity on the assumptions made when applying the impulse-momentum method, particularly in relation to frictional forces.
All they want is the magnitude of the force.freshbox said:
Not in presenting your final answer.freshbox said:
There's nothing wrong with your solution. I'm just pointing out that often when they ask for some quantity they just want the magnitude of that quantity.freshbox said:
Your error is thinking that the package ends up with zero final velocity. It just stops moving with respect to the flatcar. After the package stops sliding, the package and flatcar end up moving with the same nonzero speed.freshbox said:
In order to analyze the effect of the friction force between package and flatcar, you need to treat them separately so that the friction is an external force.freshbox said:
It all depends on the particular problem. The key thing is to realize that you can apply the impulse momentum to them separately or together, as needed.freshbox said:
Right.freshbox said:
