Johannes kepler used math to show that the planets move in perfect circles around the sun. true false

Calculate the mass of an object that has a momentum of 100kg x m/sec and velocity of 4 m/sec

Students design a model roller-coaster track. they place a rubber ball at the highest point on the track and let it go. the ball rolls along the track pulled only by the force of gravity. eventually, it comes to a stop. which change to the design will result in the ball moving the greatest distance?

Matter that emits no light at any wavelength is called