Answer:
5.33 secs
Step-by-step explanation:
Given the equation of the height modeled by the equation/
h(t) = -3.2 + 12.5t + 24.8
The object strikes the ground when the height h(t) is zero
Substituting h(t) = 0 into the expression
h(t) = -3.2t² + 12.5t + 24.8
0 = -3.2t² + 12.5t + 24.8
-3.2t² + 12.5t + 24.8 = 0
Multiply through by minus sign
3.2t² - 12.5t - 24.8 = 0
From the expression a = 3.2, b = -12.5 and c = -24.8
t = -(-12.5)±√(-12.5)²-4(3.2)(-24.8)/2(3.2)
t = 12.5±√156.25+317.44)/6.4
t = 12.5±√473.69/6.42
t = 12.5±21.76/6.42
t = 12.5+21.76/6.42
t = 34.26/6.42
t = 5.33secs
Hence the object strike the ground after 5.33 secs
