What do you think is the reason scientists use an ellipse rather than a circle as the model for a planetary orbit?

We found the centripetal acceleration of the earth as it revolves around the sun. compute the centripetal acceleration of a point on the surface of the earth at the equator caused by the rotation of the earth about its axis. (enter the magnitude. the radius of the earth is 6,371 km.)

Aray of light traveling parallel to the principal axis of a concave mirror will be reflected through the mirror's

Work = force × a. work b. energy c. distance d. momentum