A student makes a model of the sun-Earth system by swinging a ball around her head. Using this model, the student is trying to explain how Earth stays on a path around the sun. The student explains that this path is the result of -

The student explains that this path is the result of the orbit around which the Earth rotates. Every planet has an orbit which allows it to rotate around the Sun. The Earth also has a slanting axis around which the Earth rotates so that day and night can be caused. Those areas which are in front of the Sun experience day time and those which are backwards experience night time.