If an object is thrown vertically upward from the ground with an initial speed of 160 feet per second, its height (in feet) t seconds later is given by the function H(t) = −16t² + 160t.

a. Graph the function H(t).

b. Use the graph in part (a) to determine when the object will hit the ground.

c. Use the graph in part (a) to estimate how high the object will rise.