1. A 1.5 kg rock is being twirled in a circle on a frictionless surface using a horizontal rope. The radius of the circle is 2.00m and the rope makes 100 revolutions in 1.00 minutes. What is the tension in the rope? This problem has totally confused me. I don't even know what equation to use that will relate tension to the other givens in the problem! 2. What is the apparent weight of a 75.0 kg person traveling at 100 km/hour: a) over the peak of a hill with a radius of curvature = to 500m and b) at the bottom of a hollow of the same radius I'm totally lost!!! HELP!!!!!!!!!!!!!