Mathematical and Physical Journal
for High Schools
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Problem P. 4296. (December 2010)

P. 4296. At what speed must a pebble be thrown at a height of h, and at an angle of 30o, measured from the horizontal, if it is to hit the ground at an angle of 45o. (Air drag can be neglected.)

(4 pont)

Deadline expired on January 10, 2011.

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

Megoldás. A kérdéses kezdősebesség független attól, hogy a követ felfelé vagy lefelé dobjuk, értéke mindkét esetben $\displaystyle v=\sqrt{4gh}$.

Statistics:

 200 students sent a solution. 4 points: 86 students. 3 points: 66 students. 2 points: 29 students. 1 point: 12 students. 0 point: 3 students. Unfair, not evaluated: 4 solutions.

Problems in Physics of KöMaL, December 2010