Question

The height of 2 ball in meters is given by the quadratic equation y= -5+² +14t +3, where t is the time in seconds. After how many

seconds will the ball hit the ground?

Answer 1

Answer: after 3 seconds

when the ball hit the ground => - 5t² + 14t + 3 = 0

⇔ (5t + 1)(t - 3) = 0

⇔ t = 3 or t = -1/5

but t is a positive integer => t = 3

so the ball will hit the ground after 3 seconds

Explanation: