An elevator is stopped at the ground floor. It starts moving upwards at constant acceleration a>0 for 5 seconds. It then keeps a constant speed for 35 seconds. Finally, it slows down with an acceleration of the same magnitude (but opposite direction) -a, until it comes to a halt at the top floor. The top floor is 340 meters above the ground floor.
(a) What is the maximal speed v of the elevator? V=
(b) What is the acceleration a? a=