



 
Hi Megan. I think you meant to write the formula as
We ignore air resistance for this question, so we know that if the rocket takes 20 seconds to go all the way up and come back down to the level of the launch, then at time t=10 seconds it was at the maximum height. So if we can determine how long it takes to return to the level of the platform, we can answer the question (B). So h(t) = h_{0 } when the rocket returns. That means
and since v_{0} = 460, then t = 460/16 = 28.75 seconds. At half that time, the rocket has reached the apex of its flight. This is the answer to part (B). Now you want to calculate h(t) when t = (your answer to part B), v_{0 } = 460 and h_{0 } = 40:
That will answer part (A) of your question. For part (C), use the same equation. You want to find t when you know that h(t) = 0 (that's ground level), v_{0 } = 460 and h_{0 } = 40. You may need to use the quadratic formula to find the time t. Hope this helps,
 


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