On a ride in a theme park, a carriage of mass 450 kg is travels horizontally at a speed of 18 m s–1. It passes through a shallow tank containing stationary water. The tank is 9.3 m long. The carriage leaves the tank at a speed of 13 m s–1.
e) For the carriage in (b) passing through the water-tank, determine:
i) its total loss in kinetic energy.
ii) the gain in kinetic energy of the water that is moved in the direction of motion of the carriage.
in previous questions ive worked out the water weight to 118.42kg and the speed it moves at after being hit is 19m/s
KE = 1/2mv2 or kinetic energy = 0.5 x mass x velocity squared
The Attempt at a Solution
the bit that is confusing me is that it wants you to work it out in terms of the conservation of energy but when i put the maths in:
0.5x118.42 x 19^2 = 21374.81J is the answer i get.
the overall energy lost by the carriage is 34875J
i was thinking that asking for how it relates to conservation means that it should be the same as the energy loss by the carriage but i cant get that no matter what i try? am i doing the maths right here?
if those numbers are correct, is there a way to explain where the other 13500.19J of energy goes?