# RE: 400N P3D Rocket

```> whlie looking at the P3D pictures, i noticed the one of dick daniels
> holding the 400 Newton rocket in his hands. it made we wonder
> just how much
> power is 400N. to satisfy my curiosity i'd thought i'd ask so
> here goes:
> between me and my bicycle we weigh 115 Kg. if i were to strap
> on the P3D
> 400N rocket to my bicycle, how long would it take me to
> accelerate from a
> zero to 100 kilometers per hour (assume no friction and a
> level surface)?

A little physics. :-)  9.81N is the force exerted by a 1kg mass on the
ground when it's at rest, i.e. 1kg wt (weight)

Therefore, 400N = 400/9.81 kg wt = 40.77 kg wt.

Not enough to lift the average adult off the ground, but plenty to push
things around in space. :-)  Would also be a useful boost for that bicycle.
:-)

I hope my unit conversion is correct. ;-)

NB:  The conversion from Newtons to kilogram weight was done by assuming
that the accelleration caused by gravity is 9.81 m/s^2 at the Earth's
surdace, and 1N is the force required to accelerate 1kg by 1m/s^2.

The term "kilogram weight" refers to the weight (reaction force of the
supporting surface) on a 1kg mass at rest at sea level.  Strictly,
"kilogram" is a unit of mass, not weight, and Newtons is more correct to use
in this context (not people persist ;) ).

I suspect a lot of people already know this, but it's included for
informational purposes (and hopefully, my high school physics isn't too
rusty! :) ).
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