The projectile hit the ground approximately at t = 5.3 seconds.
It is given that projectile with an initial velocity of 48 feet per second is launched from a building 190 feet tall.
It is required to find when will the projectile hit the ground if the projectile equation is [tex]\rm h(t)= -16t^2+48t+190[/tex]
It is defined as the graph of a quadratic function that has something bowl-shaped.
We have the projectile equation:
[tex]\rm h(t)= -16t^2+48t+190[/tex] .....(1)
When it hit the ground the value of h(t) = 0, equate the equation(1) with 0
We get:
[tex]\rm 0= -16t^2+48t+190[/tex]
or
[tex]\rm 16t^2-48t-190= 0[/tex]
It is a quadratic equation,
Compare with the equation [tex]ax^2+bx+c=0[/tex]
a = 16, b = -48, and c = -190
By using the formula:
[tex]\rm x= \frac{-b\pm\sqrt{b^2-4ac} }{2a}[/tex]
[tex]\rm t= \frac{-(-48)\pm\sqrt{(-48)^2-4(16)(-190)} }{2(16)}\\\\\rm t= \frac{48\pm{(120.266)} }{32}\\[/tex]
t = -2.25 or t = 5.25
Time can not be a negative quantity, so leave the negative value of 't'.
So, t = 5.25 ≈ 5.3 seconds
Thus, the projectile hit the ground at t = 5.3 seconds.
Know more about the parabola here:
brainly.com/question/8708520