Archive for December, 2009
Estimate The Kinectic Energy Of The Earth With Respect To The Sun As The Sum Of Two Terms…?
(a) that due to its daily rotation about the axis, and (b) that due to its yearly revolution about the sun. [assume the earth is a uniform sphere with mass = 6.0 x 10^24 kg and radius = 6.4 x 10^6 m, and is 1.5 x 10^8 km from the sun]
Alternative Energy – Drilling To Create Electricity From Geothermal?
I recently read that it might be possible to drill a hole down into the earth to a depth where the rock is naturally very hot, pump water into the drill hole and then power a turbine with the steam that is created to generate energy. (It’s like a DIY version of electricity generated from natural geysers). It’s clean and can be done almost anywhere. Has anyone heard of this? Is this a viable alternative energy?
Which Situation Describes A System With Decreasing Gravitational Potential Energy?
1) a girl streching a horizontal spring
2)a bicyclist riding up a steep hill
3) a rocket rising vertically from earth
4) a boy jumping down from a tree.
please help