Mathematical and Physical Journal
for High Schools
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Problem P. 4155. (April 2009)

P. 4155. The electrical power of a vacuum cleaner is 1 kW. According to its description its airflow is 52 litre/s. The diameter of the tube is 3 cm. What percent of the total power is used to accelerate the air?

(4 pont)

Deadline expired on May 11, 2009.


Statistics:

115 students sent a solution.
4 points:79 students.
3 points:6 students.
2 points:1 student.
1 point:15 students.
0 point:6 students.
Unfair, not evaluated:8 solutions.

Problems in Physics of KöMaL, April 2009