An astronaut with a mass of #75 kg# is floating in space. If the astronaut throws an object with a mass of #12 kg# at a speed of #4/5 m/s#, how much will his speed change by?

1 Answer
Feb 28, 2016

The astronaut will move at #0.128m/s#

Explanation:

The momentum of the astronaut and the thrown object is equal, so if we denote:

#m_1#-mass of the astronaut

#m_2#-mass of the object thrown

#v_1#-the velocity of the astronaut

#v_2#-the velocity of the object

then we can write that:

#m_1*v_1=m_2*v_2#

#v_1=(m_2*v_2)/m_1#

#v_1=(12*0.8)/75#

#v_1=128/750=0.128#