A ball is tossed straight up from the surface of a small, spherical asteroid with no atmosphere. The ball rises to a height equal to the asteroid's radius and then falls straight down toward the surface of the asteroid. The acceleration of the ball at the top of its path is:

a. at its maximum value for the ball's flight.
b. equal to the acceleration at the surface of the asteroid.
c. equal to one-half the acceleration at the surface of the asteroid.
d. equal to one-fourth the acceleration at the surface of the asteroid.

An airplane travels from st. louis to portland, oregon in 4.33 hours. if the distance traveled is 2,742 kilometers. what is the airplane's average speed? - the airplane returns to st. louis by the same route. because the prevailing winds push the airplane along, the return trip takes only 3.75 hours. what is the average speed for this trip? - the airplane refuels in st. louis and continues on to boston. it travels at an average speed of 610 km/h. if the trip takes 3.75 hours. what is the flight distance between st. louis and boston?