Problem P. 4563. (October 2013)
P. 4563. A steam funicular railway is to be built to Hill Gellért. The top of the hill is 84 m higher than its foot. The total length of the straight slope is 140 m. There are two cars of equal masses, hung by cables at the two sides of a pulley, and one of them travels uphill whilst the other one travels downhill. In each car 40 people can travel. The funicular is loaded the most when there are 40 people in the car which is travelling up, while the other car is empty. The mass of each car is 5 tons. The average weight of a passanger is 70 kg. The coefficient of rolling friction on the iron rails is 0.005. Calculate the output of the steam engine in horse power, if one trip lasts for one minute. (The stiffness and the mass of the cable, the rotational inertia of the pulley, and air drag can be neglected in this estimation.)
(4 pont)
Deadline expired on November 11, 2013.
Sorry, the solution is available only in Hungarian. Google translation
Megoldásvázlat. Kb. 54 lóerős gépre van szükség.
Statistics:
133 students sent a solution.  
4 points:  98 students. 
3 points:  23 students. 
2 points:  9 students. 
1 point:  1 student. 
Unfair, not evaluated:  2 solutions. 
