Showing posts with label momentum. Show all posts
Showing posts with label momentum. Show all posts

Thursday, June 9

Can a yacht ever travel faster than the wind ?

This seems like defiance of laws of physics, but it needs the right shape and size of sail to trap enough of the air-mass blowing in the wind. The resulting transfer of momentum can propel yachts to impressive speeds. Especially if friction is minimized – some sleek catamarans can achieve 80km/h using 35km/h winds.

Thursday, April 16

Are the planes of solar systems aligned
with the plane of their galaxy?
The orientation of a planetary system orbiting a star depends only on the initial angular
momentum of the clouds of dust and gas from which it formed. Since these small motions are
completely random, the resulting planetary system can have any orientation. The structure of the star’s host galaxy has no bearing at all on how its planetary systems align themselves. Our Solar System, for example, is inclined by about 63° to the plane of the Milky Way.