Question

A model rocket is launched with an initial upward velocity of 47 ms. The rocket's height (in meters) after seconds is given by the following. Find all values of for which the rocket's height is 27 meters.h=47t-5y^2

Answer 1

0.61 or 8.79

Explanation:

h = 47t − 5t²

27 = 47t − 5t²

5t² − 47t + 27 = 0

Quadratic formula:

t = [ -b ± √(b² − 4ac) ] / 2a

t = [ -(-47) ± √((-47)² − 4(5)(27)) ] / 2(5)

t = (47 ± √1669) / 10

t ≈ 0.61 or 8.79