Suppose a pendulum starts with a potential energy of 100 j. assuming the pendulum has a height of 0 m at the bottom of its swing, what is the maximum kinetic energy?

The maximum kinetic energy is 100 Joules

Explanation:

Considering the pendulum as an isolated system, the kinematic energy will be conserved. The kinematic energy = (potential energy) + (kinetic energy). We know that it starts at rest (i.e., with kinetic energy being 0) with 100 Joules worth of potential energy. We also know that when the pendulum crosses the bottom point at 0m it has potential energy of 0 J implying its kinetic energy is 100 J, which is its maximum.  

kepler used the data from tycho blahe (his mentor) to construct the laws of planetary motion.