Friday, 4 January 2013

Which lands first?

Test your knowledge of basic Newtonian mechanics.

If a marksman fires a bullet perfectly horizontally over a level stretch of ground and at the exact same instant drops an identical bullet to the ground, which of them hits the ground first?

Of course we are all tempted to say that the one that has been dropped will land first, and of course we will all be wrong to say that.  Both should hit the ground at the same moment.

The really surprising thing is that the fired bullet has travelled so far in the short time before it lands.


krissthesexyatheist said...

Of the top of my Norther California (swlightly hazy) head...I'll say the same time. Happy New "Year, bro. Congrats on that fine vessel you just bought.


John Chapman said...

Sure about that? Maybe on Flatworld but on Earth the bullet would be falling as the Earth curves away underneath it and should hit a fraction of a second later.

Plasma Engineer said...

Thanks John for your ever-accurate observation. I had hoped to fend that one (and I failed) by saying that the ground was level. However, as you rightly point out that is open to interpretation in the way that you propose. :)

Plasma Engineer said...

Thanks Kriss - have been having fun on the canals, and still trying to work out what I need to buy for my new toy.