4. Valentina, the Russian cosmonaut, goes outside her ship for a space walk,
but when she is floating motionless 15 m from the ship, her tether catch on a
sharp piece of metal and is severed. Valentina tosses her 2.0 kg camera away
from the spaceship with a speed of 12 m/s. How fast will Valentina, whose
mass is 70 kg, travel toward the spaceship?​