P. 4600. A soap bubble is blown with a relatively short drinking straw of diameter d, and then the bubble is left to deflate through the same straw. In one case when the diameter of the bubble was D the time during which the bubble deflated was 8 seconds. Estimate the time during which a bubble deflates
a) if its diameter is also D, and it is deflated through a wider straw of diameter 2d;
b) through a straw of diameter d, if its greatest diameter was 2D?
Deadline expired on 10 February 2014.