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Weight and force

  • Thread starter Destiny153
  • Start date
  • #1

Homework Statement


so in my physics class, we are learning about the 3 laws of motion and all that jazz bla bla bla, i get all that stuff, just not the stuff where it comes to math. i suck at math! so we had homework, no duh, and well im stuck, can i please have some help! anyone??

hear is the problem:

An astronaut has a mass of 50 kg.

A.) how much does she weigh before lift off?
B.) when her space vehicle is 6400 Km. above the earth's suface, she will weigh one quarter of what she weighed on earth. what does she weigh at this point?


Homework Equations


so there you are, ps i know this formula but i don't understand it. Fnet = ma

net force= mass times acceleration? righ?




The Attempt at a Solution



for (A.) i think that it is 50kg, because Weight is proportional to mass; equal masses at the same location in a gravitational field will have equal weights
 

Answers and Replies

  • #2
SammyS
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for (A.) i think that it is 50kg, because Weight is proportional to mass; equal masses at the same location in a gravitational field will have equal weights
Proportional is not equal.

What's the definition of weight you learned in your course?
 
  • #3
Weight: the force of gravity on the object and may be defined as the mass times the acceleration of gravity, w = mg
 
  • #4
SammyS
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So, what's the answer to (A) ? Kilograms is a unit of mass, not weight.
 

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