How fast must a plane fly along the earth's equator so that the sun stands still relative to the passengers? give your answer in both km/h and mph. the radius of the earth is 6400 km.
part a km/h
part b mph
part c in which direction must the plane fly, east to west or west to east?
express your answer using two significant figures.

In the illustration, which two simple machines are being used to enable the student to reach the door? a. inclined plane and pulley b lever and wheel-and-axle c pulley and lever d wheel-and axle and inclined plane

During cooling, the kinetic energy of the molecules falls. why does this happen? a.the motion of the molecules increases. b. the motion of the molecules slows down. c.the van der waals forces between molecules decrease d. the forces of attraction between the molecules are overcome.

Consider a small frictionless puck perched at the top of a fixed sphere of radius r. if the puck is given a tiny nudge so that it begins to slide down, through what vertical height will it descend before it leaves the surface of the sphere? [hint: use conservation of energy to find the puck's speed as a func e conservation of energy to find the puck's speed as a function of its height at what value of this normal force does the puck leave the sphere? ] here on the puck.