KöMaL - Középiskolai Matematikai és Fizikai Lapok
Sign In
Sign Up
 Magyar
Information
Contest
Journal
Articles

 

Problem P. 3898. (May 2006)

P. 3898. A horizontal disc of mass m=0,6 kg and radius R=10 cm can be rotated easily about a vertical axle. Along a radius of the disc a sheet is fixed to the disc. (The mass of the sheet is negligible.) A horizontally fired bullet, whose mass is m1=20 g, hits the sheet perpendicularly, and the disc begins to rotate at an angular velocity of \omega=20 s-1. The distance between the axle and the place of impact is r=8 cm. What was the initial speed of the bullet, if a) it is embedded in the sheet; b) it bounced back totally elastically?

(5 pont)

Deadline expired on 12 June 2006.


Statistics:

81 students sent a solution.
5 points:52 students.
4 points:15 students.
3 points:11 students.
2 points:2 students.
0 point:1 student.

Our web pages are supported by:   Ericsson   Cognex   Emberi Erőforrás Támogatáskezelő   Emberi Erőforrások Minisztériuma   Nemzeti Tehetség Program    
MTA Energiatudományi Kutatóközpont   MTA Wigner Fizikai Kutatóközpont     Nemzeti
Kulturális Alap   ELTE   Morgan Stanley