Ann the Astronaut weighs 65.0 kg.She is space walking outside the space shuttle and pushes a 350.0-kg satellite away from the shuttle at 0.70 m/s.What speed does this give Ann as she moves toward the shuttle?
A)0.13 m/s
B)3.8 m/s
C)590 m/s
D)290 m/s
E)7.7 m/s

Question

Quizplus · Accepted Answer

According to conservation of momentum, the momentum of the system before and after the push must be the same. Let v be the speed that Ann moves towards the shuttle after the push.

Initial momentum of system = Final momentum of system

(65.0 kg)(0 m/s) + (350.0 kg)(0.70 m/s) = (65 kg + 350 kg)v

v = (350 kg * 0.70 m/s) / (65 kg + 350 kg)

v = 3.8 m/s

Therefore, the answer is B.

Ann the Astronaut Weighs 65