Wednesday, April 30, 2008

SDC Physics Quiz, Week 1

This is a duplicate of the initial thread at SDC's physics forum.

Alrighty, time to get started. This problem is entirely out of my own head, and I haven't worked it out yet, but it should be doable. As such it's pretty plain and unimaginitive, but I figured we'd start small, and build upon it. It's also part of a multi-step problem that I plan to use to fully evaluate the physics problem we know and love, a block on a ramp! (then on to the dreaded Atwoods machine!)

If anybody has any problem suggestions...I'll figure out a way to take those without cluttering this thread or resorting to e-mail. I do plan on selecting problems that demonstrate the practical side of physics as well. For example I've got a problem in mind later that looks at how fast a car can turn, before it flips over.

Feel free to discuss the problem in this thread. For those of you aren't familiar with the actual physical concepts behind this problem (and how to apply them) I'll be posting a "mini lecture" either later in the week, or with the "official" solution.


A 12kg Aluminum cube rests upon a wooden board. The coefficient of static friction (Us) is 0.2, and the coefficient of kinetic friction is (Uk) 0.1.

a) What is the required force to cause the block to begin moving?

b) What is the position of the block after 11 seconds of appling the force in part a?

c) If we stop applying the force, what is the final position of the block after it stops moving?

d) If we change the material of the block, are our calculations affected? What if we change the shape of the block?

You may use whatever methods you desire and find applicable.


Next weeks preview: We tip the board and introduce trigonometry! :::Shudder:::

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