Originally Posted by matty0610
My only question is what about newton's law? Every force has an equal and opposite force. So if this "digger" is floating and shoots the arrow, would it push its self away? Or would they get super close so that they don't give the opposite force enough time to take hold and shoot the "digger" in a separate direction?
Yes, but you need to consider the relative mass of the bolt and the "digger"
M1V1 = M2V2
So if your bolt is very light compared to your launch platform it is not going to send it back the other way with much speed. Consider firing a gun: the bullet leaves the barrel with a very high velocity but thanks to it's low relative weight the recoil does not send you flying backwards at the same speed.
Yes it will change the velocity of the launch platform, the same as a rifle will push back against your shoulder, but probably not by much. Also once the bolt is embedded it would be possible to use the wire to regain the lost momentum fairly easily. It just has to detach quickly with the sample in tow to avoid any issues due to the commet's spin though.
Originally Posted by Mach 5
If they want more power they should have mounted them the other way round. The springs are designed to bend a certain way, the way they have them mounted wont use them to their full potential.
I'm not so sure that they have them the wrong way round. There are no reinforcing sections on the spring in the picture, so that isn't going to show if they are mounted incorrectly. Also it looks like the spring is under tension in the picture, so the bend in the spring also doesn't indicate if it is set the right way round. The only indicator I can see is the orientation of the attachment points on the spring, and without knowing the exact type of spring used that is not conclusive. It is very possible that they are mounted correctly, and that the bend shown is due to tension (as in the spring has inverted from it's rest position).
An indictor that the springs are mounted correctly would be that they can fire a bolt through a 45gal drum full of gravel. That is some serious force there.
I would assume that the guys at NASA would know which way round to mount a spring, they are
fairly clever, despite what you may personally think.
Originally Posted by Hyoketsu
This thread is begging for a "took an arrow
a bolt to the comet" joke.
I used to work for NASA until ... I took .... an arrow ..... to...... OH GOD I MISS MY LEGS!Edited by GingerJohn - 12/14/11 at 3:10pm