PLEASE HELP!

To hit a ball over a tree a golfer hits the ball with a path that is modeled by h=-16t^2+80t where (h) is the height in meters and (t) is the time in seconds. Determine
Part A: The height of the ball after 1 second

Part B: The time it takes the ball to reach the maximum height

Part C: The Maximum height of the ball

Part D: The time it takes for the ball to return to the ground.

Afactory makes propeller drive shafts for ships. a quality assurance engineer at the factory needs to estimate the true mean length of the shafts. she randomly selects four drive shafts made at the factory, measures their lengths, and finds their sample mean to be 1000 mm. the lengths are known to follow a normal distribution whose standard deviation is 2 mm. calculate a 95% confidence interval for the true mean length of the shafts. input your answers for the margin of error, lower bound, and upper bound.