# Problem P. 4352. (May 2011)

**P. 4352.** A rough inclined plane of height *h*=2 m, and of angle of elevation 20^{o} consists of two parts. The two parts have the same length but the friction is different on them. At the bottom of the slope a small body was pushed, and it slid to the top of the plane and then it slid back and it just stopped at the end of the slope. *a*) What was the initial speed of the small body at the bottom of the slope? *b*) What is the coefficient of friction along the bottom part of the slope if the coefficient of friction at the top is _{2}=0.3?

(4 pont)

**Deadline expired on June 10, 2011.**

Sorry, the solution is available only in Hungarian. Google translation

**Megoldás.** \(\displaystyle a)\) 8,9 m/s.

\(\displaystyle b)\) \(\displaystyle \mu_1=0{,}43.\)

### Statistics:

96 students sent a solution. 4 points: 71 students. 3 points: 9 students. 2 points: 13 students. 1 point: 2 students. Unfair, not evaluated: 1 solution.

Problems in Physics of KöMaL, May 2011