Hover Disk- Centripetal Force

Big Questions: "How do forces cause objects to move in circles?" "What does it mean to be in orbit? How do satellites orbit planets and how do planets orbit the Sun?"

To answer these questions we used a hover disc attached to a string. We held the string and spun in a circle--imitating the gravitational pull of the moon orbiting the Earth. In order to analyze forces in two directions, two vectors need to be involved. Vectors need speed and direction. When objects move in a circle, their velocities want them to keep moving in a straight line. However normal forces from seats and doors cause the direction of our velocity to change and causes us to go in a circle. In this specific lab, there is a tension force between the person and the disk--the string. This tension force's direction is inward towards the person. When an object is shot into space, gravity pulls the object down at great speeds. The object is basically falling toward Earth, but misses because the Earth is also rotating. This is how satellites and space stations orbit Earth. The planets orbit the sun because of sun's gravitational force. Since there are no other forces in space, the planets only have the sun's gravitational field. The Earth has a velocity that is perpendicular to the Sun's gravitational pull. We then made an interaction between the person, the disk and the Earth. Between the person and the Earth, there is gravitational and normal force. Between the disk and the Earth there are normal, gravitational and friction forces.There is also a tension force between the person and the disk.