Answer:
See Explanation
Step-by-step explanation:
The question is incomplete as the value of s(t) is missing;
However, the following explanation will guide you;
I'll continue my explanation with the following assumption that:
![s(t) = 64 + 4(t-6)](https://img.qammunity.org/2021/formulas/advanced-placement-ap/high-school/8dvwqn9bapaw9mgxmfcgrwdu1fbsbuddcm.png)
Required
Determine the velocity at t = 8
To do this; first calculate s(t) by substituting 8 for t in
![s(t) = 64 + 4(t-6)](https://img.qammunity.org/2021/formulas/advanced-placement-ap/high-school/8dvwqn9bapaw9mgxmfcgrwdu1fbsbuddcm.png)
![s(8) = 64 + 4(8- 6)](https://img.qammunity.org/2021/formulas/advanced-placement-ap/high-school/k7m1l6dd9s08uzsdf3nsfhp4lpmo8kjx2r.png)
![s(8) = 64 + 4(2)](https://img.qammunity.org/2021/formulas/advanced-placement-ap/high-school/8p9tloa6ptxlp9duwtbpgbmm3nonfco826.png)
![s(8) = 64 + 8](https://img.qammunity.org/2021/formulas/advanced-placement-ap/high-school/ie58x5clxqsc480hz01lcffbrp4afgifm7.png)
![s(8) = 72](https://img.qammunity.org/2021/formulas/advanced-placement-ap/high-school/bhfnmuknz1owcb559tymwbkeq7zky6bd49.png)
Next, is to calculate the velocity by dividing s(t) by t where t = 8
i.e.
![Velocity = (s(t))/(t)](https://img.qammunity.org/2021/formulas/advanced-placement-ap/high-school/ga42pw082tig47j5101b8ri6ys0cx3shx8.png)
Substitute 8 for t
![Velocity = (s(8))/(8)](https://img.qammunity.org/2021/formulas/advanced-placement-ap/high-school/miajhpwzsgq0pwe6dyvaj5qh5od95h787r.png)
Substitute 72 for s(8)
![Velocity = (72)/(8)](https://img.qammunity.org/2021/formulas/advanced-placement-ap/high-school/axh3skyfi2ztbouxvruqi4u07reuts17su.png)
![Velocity = 9\ ft/s](https://img.qammunity.org/2021/formulas/advanced-placement-ap/high-school/1k6wf2i34uawhxlghfdajqefacr3h9zhwa.png)
So: all you need to do is first calculate s(8), then divide the resulting value by 8 to get your result