Freefall v Jetpack: Will He/She Stay Afloat or Crash?

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Homework Help Overview

The discussion revolves around a scenario involving a person falling from the sky with a jetpack that provides an upward force equal to the force of gravity. Participants are exploring the implications of this setup on the person's ability to stay afloat or crash to the ground, as well as the acceleration experienced during the fall.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants are questioning the relationship between the force of gravity and the upward force provided by the jetpack, with some attempting to clarify whether the force of gravity is equivalent to the person's weight. Others are discussing the implications of acceleration and speed in relation to the forces acting on the person.

Discussion Status

The discussion is ongoing, with various interpretations being explored regarding the effects of the forces involved. Some participants are providing hypothetical scenarios to illustrate their points, while others are seeking clarification on the conditions of the problem. There is no explicit consensus on the outcome of whether the person will stay afloat or crash.

Contextual Notes

Participants note that the problem does not specify the speed of the person or the exact conditions of the fall, leading to further questioning about the implications of acceleration and speed in the context of the forces described.

Dhruvish
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Homework Statement


There is a random person falling from the sky. He remembers that he has a jetpack. Unfortunately, his jetpack is weak and is only able to provide upward force equivalent to Fg.

WILL HE?SHE STAY AFLOAT OR WILL HE?SHE CRASH INTO THE GROUND?
What acceleration will he/she hit the ground?

Homework Equations


um, none

The Attempt at a Solution


I mean logically speaking, the person should stay afloat since the force of gravity is equal to the jetpacks force.
 
Physics news on Phys.org
Is Fg a force equal to the person's weight?
 
picture below illustrating the question.
 

Attachments

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F=ma

so for some time period a person is accelerating. He now a speed S
Assuming Fg is the force required to cancel out the effect of gravity, that means his acceleration will equal zero. what is his speed?
 
the question does not specify speed, just mentions the force of gravity and the upwards countering force.
 
Dhruvish said:
the question does not specify speed, just mentions the force of gravity and the upwards countering force.
Yes it does mention speed, it just doesn't matter exactly what that speed is.
Dhruvish said:
There is a random person falling from the sky.
in order for a person to be falling, they must have speed. If acceleration =0, what happens to speed
 
so, what is the final conclusion, Does the person fall or stay afloat? and if fall at what acceleration?
 
Dhruvish said:
so, what is the final conclusion, Does the person fall or stay afloat? and if fall at what acceleration?
I'm not going answer it for you...

lets try this.

jetpack man is at 1000 feet (a distance)
he falls 100 ft/s (a speed)

his speed doesn't change

what happens his altitude over time. remember that distance = speed * time
 

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