The distance s (in m) above the ground for a projectile fired vertically upward with a velocity of 4[a] m/s as a function of time t (in s ) is given bys=4[a]t−4.9t2 . Your instructor will provide you with a. Simply replace the letter with the corresponding digit. Do not multiply. For example, if [a]=1, then 4[a] is 41.

Find the answers to these questions.

find t for v=0
find v for t=4
find v for t=5
What conclusions can you draw?