Recent content by elliotr

150km/h=41.6666667m/s ==> d=(41.6666667m/s)*sqrt(2*500m/(9.8m/s^2))=417m Thar's your 417m.

I'm getting the correct answer to be 414.1m, and that is using what I explained earlier. Except I converted units wrong because I'm tired. :) 150km/h = 41m/s d=(41m/s)*sqrt(2*500m/(9.8m/s^2))=414m. This is definitely correct.

Assume it isn't moving for a second. h=500m=0.5*g*t^2 => t=sqrt(2*500m/(10m/s^2)). So it will be in the air for this long. Now assume it is moving along the x-axis for this period of time, t. The distance it will travel will simply be t*(horizontal speed). So if it is moving at 2.5km/s, the...

You're question is a bit confusing... I'll try to help... I'll assume: -You're saying the battery's voltage is reducing linearly from 1.5V to 0V over a three hour duration. -You're circuit is a battery with a resistor across it. -You said something about charge, so I'll assume current...

That's a very good point. But let's say that I bring the magnets to a halt after I feel the force of magnets wanting to move toward each other. At this point, the magnets are not moving, so no electric field exists. Yet when I let go, they will still move toward each other.

2.0 m/s/s means that there is an additional force caused by the deceleration of the elevator (negative acceleration), and F=ma. Therefore f_total = 49N - 5kg*(2m/s^2) = 39N

A better question: "Can a magnet (e.g. a permanent magnet) do work?" If no: how do magnets move together appearing to do work? What's actually doing the work (see first question). If yes: how is this possible when "magnetic forces do no work"?

Quote: "Magnetic Forces do no work" in bold, in a box, in the middle of the page. But between two magnets, what forces other than magnetic forces exist? What force causes them to move together? Thanks

According to every textbook I know of, magnetic forces do no work (e.g. David Griffiths Pg. 207). Yet this problem causes this to be hard to believe: If I take two magnets, I can set them down on a table (with a little friction). I then slowly push them toward each other, then at some point...