HELP A cannonball is fired upward with a velocity of 280m/s.

a. How much time does the cannonball take to reach its maximum height?

b. How high does the cannonball go before falling back to the ground?

c. How much time is the cannonball in the air?

I will award 15 points to the person that solves it!

"curse these trig-loving pirates! " devora mutters as she looks at the map. then, after thinking for a moment, she walks back to the entrance of the secret cave, measuring 48 meters along the way. after performing a calculation, devora walks back to the empty treasure, faces the entrance, and turns a certain number of degrees to her left before walking 89 meters to the treasure. supposing that the angle at the cave entrance is acute and that devora's calculations were correct, how many degrees did she turn?