19. The height h (in feet) of a certain rocket (launched from the top of a building)
t seconds after it leaves the ground is modeled by h(t) = -16t? +64t + 260.
a. Find the maximum height reached by the rocket.
(2 points)
(2,324
b. Find how long it takes for the rocket to hit the ground. (1 points)

Find a parametrization for the curve「and determine the work done on a particle moving along γ in r3 through the force field f: r^3--r^3'where f(x, y,z) = (1,-x, z) and (a) im (γ) is the line segment from (0,0,0) to (1,2,1) (b) im (γ) is the polygonal curve with successive vertices (1,0,0), (0,1,1), and (2,2,2) (c) im (γ) is the unit circle in the plane z = 1 with center (0,0,1) beginning and ending at (1,0,1), and starting towards (0,1,1)