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 catches 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. a. How fast will Valentina, whose mass is now 68 kg, travel toward the spaceship? b. Assuming the spaceship remains at rest with respect to Valentina, how long will it take her to reach the ship?