I need help with these questions

1.

A stone is thrown straight up from the edge of a roof, 600 feet above the ground, at a speed of 18 feet per second. A. Remembering that the acceleration due to gravity is -32 feet per second squared, how high is the B. At what time does the stone hit the ground? :] C. What is the velocity of the stone when it hits the ground? .:] n 4 3 Given Rn = 6 5 6 , express the limit as n -> oo as a n n n i = .b definite integral, that is provide a, b and f (@) in the expression f(x) dx. a a = b f(ac) =