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1. ### Calculating the covariance of two discrete random variables

Thank you for chiming in; it's good to know I'm not the only one who thought the wording was a bit murky.
2. ### Calculating the covariance of two discrete random variables

Homework Statement If the random variables T and U have the same joint probability function at the following five pairs of outcomes: (0, 0), (0, 2), (-1, 0), (1, 1), and (-1, 2). What is the covariance of T and U? Homework Equations σxy = E(XY) - μx⋅μy The Attempt at a Solution My issue with...
3. ### 3D moments - what am I doing wrong?

Homework Statement A 200N force is applied to the handle of the hoist in the direction shown. The bearing A supports the thrust (force in the direction of the shaft axis), while bearing B supports only radial load (load normal to the shaft axis). Determine the mass 'm' which can be supported...
4. ### Conceptual question regarding the conservation of energy

Thank you! For some reason, I was fixated on the element surface being at a constant temperature.
5. ### Conceptual question regarding the conservation of energy

Hi PF, I've got a very trivial conceptual question regarding the conservation of energy with respect to thermodynamics and heat transfer that I can't seem to figure out. Suppose I have an electric heating element with a 240 volt, 30 amp supply, in contact with a solid volume of an arbitrary...
6. ### First-order spring/damper system in parallel

I've thought about this more since posting, and I'm confident that k can be solved by k = F/x since the damper provides no resistance when the velocity is zero. This whole thread can be deleted if a moderator wishes. Sorry for the waste of bandwidth!
7. ### First-order spring/damper system in parallel

Homework Statement A viscous damper, with damping constant b, and a spring, with spring stiffness k, are connected to a massless bar. The bar is displaced by a distance of x = 0.1m when a constant force F = 500N is applied. The applied force F is abruptly released from its displaced position if...