Recent content by ErikD

Using a windmill to convert the car's kinetic energy when braking seems kinda not optimal. Using a flywheel (if you want to use it to accelerate again) or some kind of spring for that is much better.

It's done using http://en.wikipedia.org/wiki/Quasar" . You can take two of them and measure the distance at some point in the Earth's rotation. Now you wait until you get to that exact point in the Earth's rotation again and you check how long it took. Watch this video for a better...

There are 86,400,000 milliseconds in a day. A satellite in geostationary orbit travels a distance of around http://en.wikipedia.org/wiki/Geostationary_orbit" per day. So per day it's orbit could be off by 265,000 / 86,400,000 = 0,0031 km. The nice thing is that the changes in the length of a...

Mythbusters actually tested this:

Just quote the http://en.wikipedia.org/wiki/Conservation_of_energy" . When the car is standing still the turbine isn't moving. When the car is moving the turbine will move. So the energy for the turbine's movement comes from the car's movement. And because of the law of conservation of energy...

Thanks, that clears up my confusion.

Sorry I should have been a bit more clear. Yes the block is in equilibrium. Fr is the force of friction. Fr = W sin(\theta) so the block isn't moving. Isn't the magnitude of a force the amount of Newtons the force is strong? So don't the magnitudes of the components have more Newtons than the...

[PLAIN]http://upload.wikimedia.org/wikipedia/en/7/7a/Friction.png I can decompose W to get Fn and -Fr. Fn = W cos(\theta) -Fr = W sin(\theta) I know I'm allowed to decompose forces like that but I'm a bit confused as to why. Cause |Fn| + |Fr| > |W| (for the angle in this picture). So...

You might want to watch the BBC documentary http://www.bbc.co.uk/programmes/b00fyl5z" I found it very useful in simply describing the history and our current understanding of time.