If I have the equation $y'' = -g -by'$, I know that a rock was thrown straight up from a specific height h, and hit the ground at time t, how do I calculate its initial velocity?
I don't understand what I use for y'' in order to figure this out?
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1How do $y,g,b$ relate to $h, t$? – MathematicianByMistake Apr 15 '16 at 12:04
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b is the air resistance, and it is known. g is the gravitational force, and y is the vertical position. – Mikee Apr 15 '16 at 12:07
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So $y(0)=h$, and $y(t)=0$ sort of thing? – KR136 Apr 15 '16 at 12:12
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You're going to have to consider upwards motion and downwards motion separately since the equations of motion are different. Therefore you will need to calculate the maximum height and the time taken to reach this, ad well as the time to descend... – David Quinn Apr 15 '16 at 15:18