You are lying on a beach, your eyes 20cm above the sand. just as the sun sets, fully disappearing over the horizon, you immediately jump up, your eyes now 150 cm above the sand, and you can again just see the top of the sun. if you count the number of seconds until the sun fully disappears again, you can estimate the earth’s radius. but for this problem, use the known radius of the earth to calculate the time t.

When considering gravity acceleration and the force of acceleration, what must be true? a. the direction of acceleration must be perpendicular to the direction of the force. b. the direction of the force and the direction of acceleration must be the same as each other. c. the direction of the force and the direction of acceleration must be opposite of each other. d. the mass of the body must be the same as the acceleration of the body.