An open rail wagon is coasting along a horizontal track at 13.00 m s1, i.e. it is not being pushed or pulled along. The wagon has a mass of 3200 kg. Rain is falling into the wagon, filling it up at a rate of 2.000 105 m3 s 1 .

(a) Calculate the mass of the wagon after an hour of rain (1)

(b) Calculate the velocity of the wagon after an hour of rain (2)

(c) The rain is filling up the wagon at the same rate as before, but is being blown into it by a following wind, so that it hits the wagon at an angle of 2 to the vertical, in the same direction as the wagon is travelling. After an hour of rain, what is the velocity of the wagon? (3)