Step-by-step explanation:
(I'm not sure if you still needed help--you posted twice. But here is the answer anyway.)
It looked like people were helping you with the first 2, so l'll pick up from there.
3. The graph changes direction 3 times, so it shows 3 turning points.
4. x^4 is the minimum degree polynomial model, because there are 3 turning points.
5. Look at where the graph was highest. 180 appears to be the closest number to that peak, so 180 sec is correct.
6. Look at the rise again. Where is the accelaration placed on the left side of the chart? It looks to me like 3 is closest.
I'll be waiting in the comments if you need help. :)