MATH
posted by Steph .
h=16t2+80t+96
Use this position polynomial to calculate the following:
1.The height of the object after 2 seconds
2.The height of the object after 4 seconds
3.How long the object will take to reach the ground?
4.Write the position function for an object that is thrown upward from a 180 ft. building with an initial velocity of 20 ft/sec.
1. 192
2. 150
I am not sure how to do numbers 3 and 4 and I am not sure If I did 1 and 2 right?
Thanks in advance!

#1. ok
#2. I get 160  better check again
#3. solve for t when h=0
#4. 180 + 20t  16t^2