The distances(in m) above the ground for a projectile fired vertically upward with a velocity of 4[a]m/s as a function of timet(in s) is given by...

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 by s=4[a]t-4.[b]t^2

a=4 b=9 

Find the answers to these questions.

• find t for v=0 Solve with work
• find v for t=4 Solve with work
• find v for t=5 Solve with work
• What conclusions can you draw?