986 (b) A car of empty mass 100 kg coasts in a rain falling vertically relative to the ground. (No external x force is applied to car.) The car's initial (empty) velocity is 6 m/s. (1) When its mass has reached 150 kg, what is its velocity? (A trivial 0 question, but to be used in comparison with the next part.) 0 0 0 0 (2) Suppose water leaks out of the bottom of the car at the same rate it falls into the car, so that the car's mass remains constant (100 kg). What is the velocity of the car after 50 kg of water has fallen into (and out of) the car? (Here you need Newton's 2 Law in general form to get a differential equation.) (3) Why (for what physical reason) is the car slowed down in Part (2)? (4) Just as a matter of interest, if you didn't know how to get a rigorous solution to (2) by a differential equation, how close would the answer to (2) come if you approximated the problem by saying that the 50 kg of water that falls in comes out at the average velocity between first and final velocities