A 100-kg astronaut floating in space holds a 10-kg object. Then the object is tossed at 50 m/s. How fast does the astronaut go after tossing the object?

velocity is 5 m/s

Explanation:

mass of astronaut (M)=100kg

mass of object (m)=10kg

Initially they are rest , so initial velocity (u)= 0 m/s

Final velocity of object ;

let final velocity of astronaut = (Unknown)

Now , By conservation of linear momentum

Initial momentum = Final momentum

Now insert values

Further simplifying

So,

So, velocity is 5 m/s (the negative sign is due to direction)