Zero accerlation for spacewalking astronaut and sattelite?

[BadaBadi]

1. An 8- kg spacewalking astronaut pushes off a 640 kg satellite, exerting 100N force for the 0.5s it takes to straighten his arms. How far apart are they after 1 minute?

Homework Equations

3. So, I calculated the the accelration of the spaceman and the satelite during contact. My school has the solutions of the problems posted ( its an old assignment), and what I don't understand is that they calculate the accerlation and also the final velocities but then they go on to calculate the distance after contact with 0 accerlation. I don't understand why they take the accerlation after the contact to be 0. Sorry if it sounds like a stupid question

 

[Delphi51]

Welcome to PF, Bada.
While his hand is pushing on the spacecraft the spacecraft pushes back on his hand according to Newton's 3rd law. This force causes him to accelerate. After his hand loses contact, there is no pushing, no force on the astronaut so he doesn't accelerate.

 

[kerimek]

.I would like to clarify that there are two different scenarios being discussed here - one involving the acceleration of the spacewalking astronaut and satellite during contact, and the other involving the distance between them after 1 minute.

In the first scenario, the acceleration of the astronaut and satellite during contact can be calculated using the equation F=ma, where F is the force exerted, m is the mass of the object, and a is the acceleration. In this case, the astronaut exerts a force of 100N and the combined mass of the astronaut and satellite is 648kg. Therefore, the acceleration during contact is 100N/648kg = 0.154 m/s^2.

In the second scenario, after the contact, the acceleration of the astronaut and satellite becomes 0. This is because once the astronaut pushes off the satellite, there are no other external forces acting on them and they continue to move at a constant velocity. This is known as the law of inertia, which states that an object will remain at rest or in uniform motion unless acted upon by an external force.

To calculate the distance between the astronaut and satellite after 1 minute, we can use the equation s=ut+0.5at^2, where s is the distance, u is the initial velocity (which is 0 in this case), a is the acceleration, and t is the time. Since the acceleration is 0, the distance between the astronaut and satellite after 1 minute will simply be 0.5at^2 = 0.

I hope this explanation helps to clarify any confusion. It is important to remember that in physics, different scenarios can have different equations and principles applied to them, and it is essential to carefully consider the context and conditions of the problem at hand.