Please help don't know how to do 1 and 2

tosave#Q1 1. [-/3 Points] DETAILS SCALCET9 3.7.009. The height (in meters) of a projectile shot vertically upward from a point 3 m above ground level with an initial velocity of 21.5 m/s ish = 3 + 21.5t - 4.9t2 after t seconds. (a) Find the velocity (in m/s) after 2 seconds and after 4 seconds. v (2) = 1 m/s (4) = m/s (b) When does the projectile reach its maximum height? (Round your answer to two decimal places.) (c) What is the maximum height? (Round your answer to two decimal places.) (d) When does it hit the ground? (Round your answer to two decimal places.) (e) With what velocity (in m/s) does it hit the ground? (Round your answer to two decimal places.) m/s Need Help? Read it Watch It 2. [-/3 Points] DETAILS SCALCET9 3.7.017. A spherical balloon is being inflated. Find the rate (in ft2/ft) of increase of the surface area (S = 4xr2) with respect to the radius r when r is each of the following. (a) 3 ft it 2 / ft (b) 6 ft + 2 / ft (c) 9 ft + 2 / ft Need Help? Read It Watch It