Posted by sarah on .
i was wondering if i did this right
A cannon ball is shot from a cannon on top of a hill that is 73.5 meters above sea level. The cannon ball leaves the cannon with a velocity of 9.8 m/s. Write and solve a quadratic equation to determine when the cannon ball will reach sea level.
0 = 4.9t² + 9.8t + 73.5
0 = 4.9(t²  2t  15)
0 = 4.9(t  5)(t + 3)
t  5 = 0 and t + 3 = 0
t = {5,3}
t = 5 since t = 3 is not acceptable negative value.
Hence, the cannon ball will reach sea level at 5 seconds.

algebra 
bobpursley,
yes, assuming it was shot horizontally.