An astronaut of mass 150 kg is floating freely (at rest) in outer space. She is holding a 25 kg can (not part of her mass mentioned earlier). She throws the can forward with a velocity of 12 m/s. How fast will she move backwards after she throws the can?

"i have always loved contemporary art and made it a general goal to work within the field. after a few nonprofit internships at museums and galleries, i decided to try the for-profit art world and was offered a job as the ad assistant at the magazine. i much prefer the pace of the for-profit art community and have stayed with the company for three years, with a promotion to an account manager last spring."

i just did this and got a 100.