What is the value of gravitational acceleration at a distance half of earth radius above the earth's surface

An equinox occurs when a. neither end of earth's axis is tilted toward or away from the sun. b. the north end of earth's axis is tilted away from the sun. c. the north end of earth's axis is tilted toward the sun. d. earth's axis is parallel to the sun's rays. select the best answer from the choices provided a b c d

Compare the horizontal displacement of the two balls as they travel to the ground. what do you observe?

Which of the following are appropriate acceleration units?