Water Clock

 I need a much better water clock to do this experiment Rule of odds - Todays job. A cart is rolled down the track. As it passes a bell it rings the bell. We try and make the time between each bell ring the same. As the cart is accelerating, the gap between each bell gets larger. in the ratio 1:3:5:7 etc Once this is set up then I use water coming out from a tap to fill up different measuring cylinders. The amount of water is in the ratio 1:4:9:16:25