If an arrow is shot straight upward on the surface of the moon with initial velocity 60m/s, its height after t seconds is given by h(t) = 60t - 0.8t². (a) What is the velocity of the arrow after 1 second? (b) At what time t > 0 will the arrow hit the moon? (c) What is the velocity of the arrow when it hits the moon? (d) At what time does the arrow reach its maximal height?​ Show your working out!