Gravity's affect on weight in an elevator

[bholloway]

Homework Statement

For this problem I need to figure out how weight changes in a moving elevator. So for example if I had a 20lb dumbbell on a scale and went up 3 floors would the actual weight of the dumbbell change? How would this show on the scale. Then I have the same question except this time the elevator is going down? I really just need the basic concept of how gravity affects the weight. Thanks.

Homework Equations

No equations needed, its just a theory problem.

The Attempt at a Solution

 

[CompuChip]

Hi bholloway, welcome to PF.

When the elevator is not moving, which forces are acting on the weight.
When the elevator is moving upwards, which additional forces are present? Can you describe their magnitude in terms of the acceleration of the elevator? Can you also then compute the total force (hint: Newton's second law) which the block feels (draw a free-body diagram) and the corresponding acceleration (if you want, the "effective" gravity).

 

[baba89]

I can provide some insight into how gravity affects weight in an elevator. The basic concept is that weight is a measure of the force of gravity acting on an object. In an elevator, the force of gravity is still acting on the object, but the elevator itself is also experiencing acceleration due to its movement. This acceleration can either add to or subtract from the force of gravity, resulting in a change in the perceived weight of the object.

In the scenario given, if the elevator is going up, the acceleration of the elevator will add to the force of gravity, making the dumbbell feel heavier. This will be reflected on the scale, as it will show a higher weight reading. On the other hand, if the elevator is going down, the acceleration will subtract from the force of gravity, making the dumbbell feel lighter and resulting in a lower weight reading on the scale.

In both cases, the actual weight of the dumbbell does not change. It is the perceived weight that changes due to the acceleration of the elevator. This concept can also be applied to other scenarios, such as being in a car or on a rollercoaster. The force of gravity is always acting on objects, but other forces, such as acceleration, can affect the perceived weight.

I hope this explanation helps in understanding how gravity affects weight in a moving elevator. As a scientist, it is important to understand the fundamental concepts of gravity and how it interacts with other forces to impact the world around us.