How the discoverd of johannes kepler has been benefits the world now

Ineed the answers for these promblems i have

If jerome is swinging on a rope and transferring energy from gravitational potential energy to kinetic energy, is being done.

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.