Could someone take a look at my answers?

After being thrown from the top of a tall building, a projectile follows a path described parametrically by (x, y) = (48t, 400 − 16t2), where x and y are in feet and t is in seconds.

(a) How many seconds did it take for the object to reach the ground, where

y=0? How far from the building did the projectile land?

(b) How fast was the projectile moving at t = 0 when it was thrown?

(c) Where was the projectile when t = 2, and (approximately) how fast was it moving?