KöMaL - Mathematical and Physical Journal for Secondary Schools
Hungarian version Information Contest Journal Articles News
Entry form to the contest
Problems and solutions
Results of the competition
Problems of the previous years



Order KöMaL!

Competitions Portal

P. 4098. A spaceship gets into an interplanetary dust cloud. The average mass of the grains of the cloud in a cubic metre is is 0.02 mg. The speed of the spaceship with respect to the cloud is 10 km/s, the area of its cross section which is perpendicular to its speed is 50 m2. The collision between the grains and the spaceship is totally inelastic. What must the thrust of the engine be in order not to change the speed of the spaceship?

(4 points)

Deadline expired on 11 November 2008.

Statistics on problem P. 4098.
208 students sent a solution.
4 points:89 students.
3 points:69 students.
2 points:18 students.
1 point:18 students.
0 point:14 students.

  • Problems in Physics of KöMaL, October 2008

  • Our web pages are supported by:   Ericsson   Google   Cognex   Emberi ErőforrĂĄs TĂĄmogatĂĄskezelő   Emberi ErőforrĂĄsok MinisztĂŠriuma  
    OktatĂĄskutatĂł ĂŠs Fejlesztő IntĂŠzet   Nemzeti TehetsĂŠg Program     Nemzeti
KulturĂĄlis Alap   ELTE   Morgan Stanley