SOLUTION: the height h, of a ball above ground t seconds after it is thrown vertically upwards can be approximated by the formula h=vt-5t squared, wher v is the intial speed with which the b

Question 35777: the height h, of a ball above ground t seconds after it is thrown vertically upwards can be approximated by the formula h=vt-5t squared, wher v is the intial speed with which the ball is released in meters per second.
at what two times will a ball be 105m above ground if it is thrown vertically upwards with an initial speed of 50m/s
Answer by Earlsdon(6294) (Show Source): You can put this solution on YOUR website!

Substitute v = 50 and h = 105 and solve for t.
Subsubtract 105 from both sides and simplify.
Solve this quadratic equation by factoring.
Apply the zero products principle.
Factor.
Apply the zero products principle again.
and
If then
If then
The two times are:
t = 3 seconds.
t = 7 seconds.
You check these solutions by substituting into the original equation and solving for h.
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