Q1. A planet of mass 6.00 1025 kg is in a circular orbit of radius 2.00 1011 m around a star. The star exerts a force on the planet of constant magnitude 5.03 1023 N. The speed of the planet is 4.09 104 m/s. All through this half "year", how much work is done on the planet through the gravitational force acting on planet?
Q2. A car accelerates uniformly from rest and reaches a speed of 16 m/s in 10.00 s. If the diameter of a tire is 57.0 cm, find (a) number of revolutions the tire makes throughout this motion, assuming that no slipping occurs. (b) What is the final rotational speed of a tire in revolutions per second?