Problem statements
Solution video – H15.A
Solution video – H15.B
Reminder: Please submit HW15.A. No credit will be given for submitting the wrong homework assignment.
DISCUSSION THREAD
Please post questions here on the homework, and take time to answer questions posted by others. You can learn both ways.
How is it possible for the weight to be negligible? Both the buoyant force and the tension forces are in the positive y direction, so how can the hemisphere shell be in equilibrium?
I am also running into this issue. I think the superstructure must have reaction forces that allow it to be in equilibrium, but I don’t understand why the question wouldn’t ask for those too.
So I figured out why this problem is weird, and it’s because the provided diagram is really confusing. The cables actually run from C to A and C to B, not C to D and C to E, like I thought. CD and CE are actually part of the flotation device.
Inara is correct– the tensions we are solving for are T_{CA} and T_{CB}. The buoyancy force is upwards, making the tension in the cables point towards the negative y direction.
Does the fact that the flotation device is hollow affect how we solve this problem at all? Do we need to change how we solve for the volume submerged and the volume of the cap?