1

enter image description here

According to this link,

An object's weight, henceforth called "actual weight", is the downward force exerted upon it by the earth's gravity. By contrast, an object's apparent weight is the upward force (the normal force, or reaction force), typically transmitted through the ground, that opposes gravity and prevents a supported object from falling.

In my picture, the elevator is accelerating upwards with an acceleration $a$. An object is attached to the ceiling of the elevator with a massless string. The actual weight of the object is $mg$. No normal force exists here, so can we say that the apparent weight of the object is the tension force $T$?

tryingtobeastoic
  • 1,002

1 Answers1

1

. . . . . so can we say that the apparent weight of the object is the tension force $T$? - Yes

Imagine that the string was a massless spring balance.
The reading on the spring balance, which is the apparent weight of the object, would be the same as that of the tension on the string.

Using $F=ma$ with "up" as the positive direction $t-mg = ma \Rightarrow T = Mg+Ma$ and that is the apparent weight of the object.

If $a=0$ then $T=mg$ which is the weight of the object.

If $a=-g$, ie the system is in free fall, $T=0$ and so the onject appears to be weightless ie the reading on a spring balance would be zero.

Farcher
  • 95,680