1 newton is the force needed to accelerate 1 kilogram of mass
at the rate of 1 meter per second² .
1 N = 1 kg-m/s² .
It's a force equal to roughly 3.6 ounces.
I think by using data collected by Tycho Brahe
The feather's vertical position 
is determined by
We take the feather's starting position to be the origin, and the downward direction to be positive. Then
so the answer is D.
A camera flash or lighting bolt because stored separated positive and negative charges --> caused them to do work by briefly lighting a bulb as the separated charges moved back together
