1. The problem statement, all variables and given/known data A small container of water is placed on a carousel inside a microwave oven, at a radius of 12.0 cm from the center. The turntable rotates steadily, turning through one revolution in each 7.25 s. What angle does the water surface make with the horizontal? 2. Relevant equations v = d / t , F = mv^2 / r 3. The attempt at a solution - We obtain speed from the v equation --> v = 2∏r / t = 0.104 m/s - Then we use the force equation to obtain --> m 0.0901 m/s^2 - Now we do --> θ = tan^-1 (.0901) / 9.8 = 0.527° I got this from the book, but my question is: Why are they taking 0.0901 as the y-component and not gravity?! The angle is w.r.t. the horizontal, so the opposite cathetus should be mg.... Centripetal accel. is working on the x-axis and mg on the y-axis, right? So, I don't quite get this... any help?? Thanks!