Please answer these step by step

019 10.0 points An engineer in a locomotive sees a car stuck on the track at a railroad crossing in front of the train. When the engineer first sees the car, the locomotive is 280 m from the crossing and its speed is 20 m/s. If the engineer's reaction time is 0.34 s, what should be the magnitude of the mini- mum deceleration to avoid an accident? Answer in units of m/s2. 020 (part 1 of 3) 10.0 points A tennis ball is dropped from 1.82 m above the ground. It rebounds to a height of 0.929 m. With what velocity does it hit the ground? The acceleration of gravity is 9.8 m/s . (Let down be negative.) Answer in units of m/s. - 5, 6975 mls