Beginning 156 miles directly east of the city of uniontown, a truck travels due south. if the truck is travelling at a speed of 31 miles per hour, determine the rate of change of the distance between uniontown and the truck when the truck has been travelling for 81 miles. (do not include units in your answer, and round to the nearest tenth.)

An astronaut on the moon throws a baseball upward. the astronaut is 6 ft, 6 in. tall, and the initial velocity of the ball is 3030 ft per sec. the height s of the ball in feet is given by the equation s equals negative 2.7 t squared plus 30 t plus 6.5s=−2.7t2+30t+6.5, where t is the number of seconds after the ball was thrown. complete parts a and b.