SOLUTION: When a projectile is fired, the vertical component of its initial velocity is such that its height h metres t seconds after firing is given by {{{h=250t-4.9t^2}}}. Determine if

Question 374292: When a projectile is fired, the vertical component of its initial velocity is such that its height h metres t seconds after firing is given by .
Determine if the projectile will reach each height.
a)2.75km
b)4.0km
Answer by nerdybill(7384) (Show Source): You can put this solution on YOUR website!

Is a quadratic (parabola) that opens downwards. We can tell because the coefficient associated with the t^2 term is negative. If so, then the vertex defines the hight point.
.
Highest point is reached when the time is:
t = -b/(2a) = -250/(2*(-4.9)) = -250/(-10.8) = 25.51
Highest point projectile will reach:

meters
kilometers
.
So, now we can answer the question:
a)2.75km (yes)
b)4.0km (no)

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