Problem statements
Solution video - H7.A
Solution video - H7.B
DISCUSSION THREAD
Please post questions here on the homework, and take time to answer questions posted by others. You can learn both ways.
HOMEWORK 7 - Sp 25
13 thoughts on “HOMEWORK 7 - Sp 25”
Leave a Reply
You must be logged in to post a comment.
Should the moment be expressed as a scalar or as a vector (with direction)?
I expressed the moment as a vector (with direction) since this was done in the lecture video.
moment is always a vector
Moments should always be in vector form
What exactly does having a equivalent force system entail? ex what should we have in our final answer? A sum of momentum and then magnitude in the i and j directions?
^moment not momentum
The way I think of it is "What if I were to move all of the forces to this one point. How would I get the same results as in the original situation (as in what forces and moment would I need to get the same results as the initial situation)"
An equivalent force system does indeed have the sum of the moments and the vector of the resulting force on the whole system. In this problem, the disk is in the x-y plane, so the resulting force vector in the system will have i and j components to it. The moment will be expressed as just a vector in the k-direction though since this is a 2D question. So you will need one force vector and one momentum vector to answer this question.
I can't access the solution video for H7A for some reason. Says it's private
I seem to be having the same problem.
Just to clarify, the resulting moment would act in the negative k_hat direction (since it is clockwise)? Also, as part of our work, do we need to show both the sum of forces in the x-direction and sum of forces in the y-direction? Is it necessary to compute the magnitude of the vector of forces in the x and y directions?
Yeah the resulting moment should be in the negative z-direction. I think you just need to show the resultant force in vector form. I do not think you need to compute the magnitude of the resultant.
It is probably best to leave the magnitude as well just because the problems usually show a magnitude and direction of forces. That is what I did but I'm sure either method works.
1