I came across these two physics questions that I have no clue how to answer.

Any help is greatly appreciated and thank you in advance!

- A crate of mass 100 kg is at rest on a horizontal floor. The coefficient of static friction between the crate and the floor is .4, and the coefficient of kinetic friction is .3. A force F of magnitude 344 N is then applied to the crate, parallel to the floor. Will the crate move, and if so, WHY?

- Two crates are stacked on top of each other on a horizontal floor. Crate #1 is on the bottom, and Crate #2 is on the top. Both crates have the SAME mass. Compared to the strength of the force F1 necessary to push only Crate #1 at a constant speed across the floor, the strength of the force F2 necessary to push the stack at the same constant speed across the floor is greater than F1 because...?

Any help is greatly appreciated and thank you in advance!

Posted: January 2011
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