Question

A person will feel less than the normal weight whenever they are moving upward

Answer 1

Answer:

False: only when the person accelerating downward

Explanation:

We can measure the "apparent weight" of a person by considering the following situation:

the person is standing on a scale. The normal reaction exerted by the scale (and so, by the floor) is actually what we perceive as "apparent weight". We call this force N (normal force), and we know that it acts upward.

At the same time, there is another force acting on the person: the force of graviity, also called (true) weight, which acts downward, and we label it with W.

Therefore, the equation of the forces on the person is:

$N-W = ma$

where we have chosen upward as positive direction, and where

m is the mass of the person

a is its acceleration

We notice the following observations:

- If the person is moving at constant speed (no matter if upward or downward), the acceleration is zero: a = 0, so the apparent weight is the same as the true weight:

N = W

- If the person is accelerating upward, then $a>0$, and so

$N=ma+W \rightarrow N>W$

So, the apparent weight will be larger than the true weight

- If the person is accelerating downward, then $a$, and so

$N=ma-W \rightarrow N$

So, the apparent weight will be less than the true weight

So, the initial statement is wrong.