An object thrown vertically upward from the surface of a celestial body at a velocity of 21 m/'s reaches a height of a= - 0.71 + 21t meters in t seconds. a. Determine the velocity v of the object after t seconds. b. When does the object reach its highest point? c. What is the height of the object at the highest point? d. When does the object strike the ground? e. With what velocity does the object strike the ground? E On what intervals is the speed increasing? a. The object's velocity after t seconds is v(t)= b. It takes the object to reach its highest point. (Simplify your answer.) c. The object reaches a maximum height of (Simplify your answer) d. The object strikes the ground after (Simplify your answer) e. The object strikes the ground with the velocity Samplify your answer! The speed is increasing on the mervaks) (Simplify your answer Type your answer in interval notation. Use a comma to separate answers at needed