Since Astronaut and wrench system is isolated in the space and there is no external force on it
So here momentum of the system will remain conserved
so here we can say

initially both are at rest
so here plug in all values


so here the astronaut will move in opposite direction and its speed will be equal to 0.20 m/s
Acceleration will be 9.81 if it goes downwards. If it accelerates upwards it will be -9.81m/s^2
Answer:
The person above me is right i had a test a couple of days ago and thats kinda what u put and got it right!
Answer:
A. Scientists use seismic computer models to measure the atmospheric conditions above the Earth's crust
Explanation:
why would use atmosphere to study the layers of earth? dont think thats possible