Plz help fil in

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.

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?

7)an object is thrown straight up with an initial velocity of 3 m/s. what is its acceleration at its maximum height? a)zero b)3 m/s2 c)-9.8 m/s2 d)none of the above