Question

A baseball is hit straight up into the air at an initial velocity of 35 m/s. How long does it take for the
baseball to reach its highest position?

and

As a traffic light turns green, a car at rest begins to move forward at a uniform acceleration of 3.1 m/s^2 [E] the same time, a truck passes through the intersection travelling at a constant velocity of 15 m.s [E] At what time does the car pass the truck?

Answer 1

v = 35 - 9.81t
when is v=0?

1/2 * 3.1 t^2 = 15t