See the attached screenshot, please answer both parts of the question. Thank you.

8. Sam hasn't realized it until just now, but the ball he lost in the tree was taken by a squirrel yesterday. The squirrel took Sam's ball all the way to downtown Chicago, to the peak of Willis Tower. Butterfingers the Squirrel then dropped Sam's ball from the top of the antennae at the top of the building, and Sam's ball falls at a rate of y = 16t feet per second in the first t seconds. Find the instantaneous speed of Sam's ball at t = 10 seconds. BONUS. Find the instantaneous speed of Sam's ball from #8 at t = 15 seconds