Eric has a mass of 80 kg. he is standing on a scale in an elevator that is accelerating downward at 1.7 m/s2. what is the approximate reading on the scale?

F = mg

m = 80kg

g = the acceleration due to gravity (approx 9.8 m/s^2) - the acceleration of the scale = 8.2 m/s^2

Thus the force = 656 Newtons, or 660 N to keep the correct number of significant figures.