A pendulum is swimging. It swings 85 complete swings and this takes 102 seconds. What is the frequency?​

It really doesn't matter for any of the questions that you've listed.

At maximum height, kinetic energy is converted in potential energy  formula: at max height, ke = ½ * 0.27kg * (16m/s) ² = 34.56 j  so the remaining pe = (41.70 – 34.56)= 7.14 j = 0.27 kg * 9.8m/s² * h  = (9.8/7.14 * 0.27)so max height h = 5.08 or 5 m 

Yup your right can give me more detail