# Physics

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An 80 kg man is riding in an elevator from the first floor to the 34th floor. The elevator and man are moving at a constant speed. What is the net force on the man in Newtons
(g=9.8)

• Physics - ,

Net force (N) = Mass(kg)* g(m/s^2)
= 80*9.8 = ___ N

It doesn't matter what floor he is on.
The constant speed does matter.

• Physics - ,

• Physics - ,

Net force is in fact equal to weight for constant speed.

Maybe the idiot computer grader is using something else besides 9.8m/s^2 for the acceleration of gravity.

• Physics - ,

Could be the idiot computer grader is using 80, and 9.8 as significant digits.

in the 80, it is one sig digit, two in 9.8

Technially, with that, the answer cannot be more than one sig digit, answer= 800
if you do two sig digits (ignoring the 80), then the answer is 780

but in any rate, it is important for you to know the force at constant speed is mg

• Physics - ,

• Physics - ,

absolutely the answer is zero. note the question it says net force .