Three astronauts equipped with jetpacks

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Homework Help Overview

The problem involves three astronauts using jetpacks to exert forces on a satellite with a mass of 121 kg in space. The forces are specified with both magnitude and direction, and the goal is to determine the magnitude of the satellite's acceleration.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to calculate the net forces in both the x and y directions, leading to a calculation of acceleration. Some participants question the inclusion of the negative sign in the final answer, discussing the concept of magnitude.

Discussion Status

Participants are engaged in clarifying the concept of magnitude versus signed values in the context of acceleration. There is a productive exchange regarding the interpretation of the results, with guidance provided on how to present the final answer.

Contextual Notes

There appears to be confusion regarding the treatment of negative values when discussing magnitudes, which may affect the understanding of the problem's requirements.

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Three astronauts equipped with jetpacks are pushing a satellite, having a mass of 121kg, through space. The forces being exerted on the satellite are F1=31.8N at an angle of 31.0 degrees above the horizontal (θ1), F2=40.0N at 60.2 degrees below the horizontal (θ2), and F3=54.7N along the horizontal.

What is the magnitude of the satellite's acceleration?

So I tried to solve it by adding all the FnetX, and Fnet Y

Fnet x= 31.8 cos 31 + 54.7 + 40.0 cos 60.2
= 27.2579 + 54.7 + 19.8789584
= 101.8368786 N

Fnet y= 31.8 sin 31 - 40.0 sin 60.2
= 16.37821 - 34.71061813
= -18.332408 N

tan θ = 101.8368786 / -18.332408
θ = -79.79506177

sin θ = Fnet x/ Fnet
sin (-79.79506177) = 101.8368786/ Fnet
Fnet = -103.47 N

Fnet = ma
a = Fnet/m
a = -103.4737987 N/121 kg
a = -0.85 m/s^2

But apparently it's wrong, can someone help please?
 
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p14r said:
Fnet = ma
a = Fnet/m
a = -103.4737987 N/121 kg
a = -0.85 m/s^2

But apparently it's wrong, can someone help please?
Did you include the minus sign in your answer? They wanted the magnitude of the acceleration.
 
Yup i did, so i shouldn't enter the negative sign?
 
p14r said:
Yup i did, so i shouldn't enter the negative sign?
No you shouldn't. Magnitudes are unsigned.
 
It worked, thank you so much!
 

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