Acceleration and weight question

Click For Summary

Homework Help Overview

The discussion revolves around understanding the weight of a 180 lb person while accelerating at a rate of 0.9 m/s². Participants explore the relationship between weight, mass, and acceleration, particularly in the context of gravitational forces.

Discussion Character

  • Conceptual clarification, Assumption checking, Mixed

Approaches and Questions Raised

  • Participants discuss the application of the formula F=ma and question the correct use of acceleration due to gravity in calculations. There are attempts to clarify the difference between mass and weight, as well as the implications of acceleration in different contexts, such as being in an elevator or on the moon.

Discussion Status

The conversation is ongoing, with various interpretations of the problem being explored. Some participants have provided guidance on how to approach the calculations, while others express confusion about the relationship between mass, weight, and acceleration. There is no explicit consensus, but several productive lines of questioning have emerged.

Contextual Notes

Participants are navigating the complexities of using pounds as a unit for both mass and weight, and there is a noted ambiguity in the original question regarding the conditions under which the person is accelerating. The discussion also touches on the effects of gravity on different celestial bodies.

  • #31
This isn't an equation. Can you please just help with the equation part. It has been 2 hrs and this is incredibly frustrating. The scales aren't moving because he is in the elevator moving at the same speed. How do I solve the question, please please help with that.
 
Physics news on Phys.org
  • #32
alexcc17 said:
This isn't an equation. Can you please just help with the equation part. It has been 2 hrs and this is incredibly frustrating. The scales aren't moving because he is in the elevator moving at the same speed. How do I solve the question, please please help with that.

We'll get through this. Stay calm. We are your friends. Put down the butter knife. Being on an elevator is new information. Are we on Earth in this elevator?
 
  • #33
Yes, we are on earth, moving upwards at an acceleration of .9 m/s^2.
 
  • #34
The equation is f=ma

weight = mass x (acceleration due to gravity + additional acceleration from motion)

lbs are awkward

weight in lbs = mass in lbs x acceleration in Earth gravities

weight in the lift going up = 180 x(1 + ? ) lbs

===

and because the question is unclear there would also be the weight an astronaut experiences inside a rocket accelerating at 0.9m/sec/sec or on a moon a little smaller than Earth's moon with a surface gravity of 0.9m/sec/sec.

Along with a decending lift 180x(1-?) lbs and even a car accelerating from the lights where the passenger will feel himself being forced back into the seat but the set of scales on the floor will still show 180lbs.
 
  • #35
This I understand! So... 180*(1.092)=196.56 lbs
 
  • #36
and since the question is unclear how about the 180lb astronaut in the rocket?
 
  • #37
Find the gravities on the moon instead of the Earth and add the acceleration?
 
  • #38
try it and see, tell us the answer you get.
 
  • #39
1.635/.9=1/x... x=.55 gravities...
180*(1+.55)=279 moon pounds?
 
  • #40
astronauts weigh less on the surface of the moon than on the earth.
 
  • #41
How would I solve it?
 
  • #42
If I have a mass of 180lbs then on the surface of the Earth my weight will be 180lbs (mass) x 1 gravity (acceleration) to give 180lbs (force) weight.

Gravity on the surface of the moon is 1/6th that on Earth so now my 180lbs mass feels like a _____ lb weight.
 

Similar threads

Replies
6
Views
3K
  • · Replies 3 ·
Replies
3
Views
971
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 9 ·
Replies
9
Views
4K
Replies
11
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
5K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 38 ·
2
Replies
38
Views
5K
  • · Replies 3 ·
Replies
3
Views
2K