Normally, on roller coasters, the cars are pulled up a lift hill and then accelerated down the descent by gravity. This imaginary roller coaster is different. The roller coaster car is to be accelerated by an initially tensioned spring so that it then runs through a loop with r=18m and then drives up a ramp. It is again accelerated by gravity and now runs through the loop in the opposite direction. The roller coaster car with the mass m = 250 kg should not fall out of the loop. The spring constant is k=6 250 Mm. a) Make a sketch of the question. b) Determine the maximum speed of the roller coaster car over the entire route. c) Calculate the height of the ramp after the loop. d) Calculate the amount by which the spring must be stretched