Acceleration and weight question

Click For Summary
SUMMARY

The discussion focuses on calculating the weight of a 180 lb person accelerating at 0.9 m/s², emphasizing the distinction between mass and weight. Participants clarify that weight is calculated using the formula F = ma, where 'a' includes both gravitational acceleration and any additional acceleration. The conversation highlights the confusion surrounding units, particularly pounds as both mass and weight, and the impact of different gravitational forces, such as those experienced on the Moon. Ultimately, the correct approach involves using the total effective acceleration to determine the perceived weight in various scenarios.

PREREQUISITES
  • Understanding of Newton's second law (F = ma)
  • Knowledge of gravitational acceleration (9.81 m/s² on Earth)
  • Familiarity with the concept of mass versus weight
  • Basic unit conversion between pounds and kilograms
NEXT STEPS
  • Learn how to convert gravitational acceleration into "g's" for various celestial bodies
  • Study the differences between mass and weight in physics
  • Explore the effects of acceleration on perceived weight in different scenarios
  • Investigate the implications of weightlessness in free-fall situations
USEFUL FOR

Students studying physics, educators teaching concepts of force and gravity, and anyone interested in understanding the effects of acceleration on weight perception.

  • #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

What is the apparent weight of a woman riding over a hump in a car?
  • · Replies 6 ·
Replies
6
Views
3K
Solving for Work Done When Accelerating a Mass
  • · Replies 3 ·
Replies
3
Views
931
Speed and apparent weight of person in reverse bungee jumping
  • · Replies 9 ·
Replies
9
Views
2K
Calculate elevator acceleration using mass
  • · Replies 9 ·
Replies
9
Views
4K
Weight of person on Earth, and on a different planet's surface?
  • · Replies 11 ·
Replies
11
Views
3K
Calculating Elevator Acceleration: Solve for F=ma
  • · Replies 3 ·
Replies
3
Views
2K
Newton's Third Law: Acceleration of box and worker
  • · Replies 2 ·
Replies
2
Views
5K
Angular acceleration of plank hanging off edge with a weight
  • · Replies 7 ·
Replies
7
Views
2K
Monkey accelerating up and down a rope
  • · Replies 38 ·
2
Replies
38
Views
5K
Force and acceleration of a rocket
  • · Replies 3 ·
Replies
3
Views
2K