This is really important. question: a space walking astronaut has become detached from her spaceship. she's floating in space while holding nothing but a wrench she is thinking about how to get back to the spaceship, which she can see 50 m from her current location. what can she do to get back to the spaceship? explain your answer using newton's law of motion

She can throw the wrench in the direction opposite to the spaceship. It's Newton's third law:

"To every action there is always opposed an equal reaction: or the mutual actions of two bodies upon each other are always equal, and directed to contrary parts."

Throwing the wrench she generates force to the wrench directed away from the spaceship. The same force is generated to her but in the opposite direction which is towards the spaceship.