Astronaut and Satellite Separation Speeds

AI Thread Summary
An astronaut with a mass of 74 kg pushes off a satellite of 420 kg with a force of 120 N for 0.82 seconds. The initial calculations included the astronaut's weight, which is irrelevant in space, leading to confusion in determining acceleration and velocity. The correct approach focuses solely on the force applied and the astronaut's mass to calculate acceleration. After clarifying the method, the astronaut successfully determines the correct speed after separation. This discussion emphasizes the importance of isolating relevant forces in physics problems.
meran
Messages
2
Reaction score
0

Homework Statement



An astronaut of mass 74 kg pushes off a satellite of mass 420 kg, exerting a force of 120 N for the 0.82 s they are in contact.

Homework Equations



What is the speed of the astronaut after they have separated?
What is the speed of the satellite after they have separated?

The Attempt at a Solution



The astronaut's weight is -726 N. If he were to push with 120 N, the combined forces would equal -734.8 N. Therefore, from F=ma, acceleration would be -9.93 m/s/s and veloctiy (-9.93=v/.82) would equal -8.14 m/s. However, that is not the correct answer. I have a feeling something in my initial set up is wrong. Any ideas?
 
Physics news on Phys.org
The astronaut's weight has nothing to do with it (he's in space!). You only need to consider the masses. I don't get where you got the -734.8 N from. There is only the one force acting. Other than that, I think you are on the right track.
 
Last edited:
How much does 120N make 74kg accelerate? Thats all you need to consider to get the accelaration of the astronaut.
 
Alright! I got it! Thank you so much for your help.
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

How far apart are the astronaut and satellite after 8.67 minutes?
Replies
10
Views
2K
Time for astronaut to reach the satellite
Replies
5
Views
1K
Momentum of Astronaut and Satellite
Replies
6
Views
10K
What is the distance between the astronaut and the satellite after 1.0 min?
Replies
2
Views
19K
Finding the astronaut's weight on a planet's surface
Replies
9
Views
3K
Astronaut throwing a Wrench in space problem again
Replies
3
Views
7K
Astronaut in space, calculating velocity etc
Replies
12
Views
5K
What is the weight of an astronaut inside a satellite in circular orbit?
Replies
10
Views
2K
Solving the Spacewalking Astronaut Problem
Replies
1
Views
2K
Astronaut floats outside spacecraft
Replies
38
Views
4K

Hot Threads

Recent Insights

Back
Top