Full explanation please I’m asking kindly

1. Thé speed of sound is 331 m/s. How much time will it take for the sound from a fire work explosion to travel 1 kilometer?
(Note: 1 km= 1000 meters)


2. An object that is originally moving at speed at 20 m/s accelerates uniformly for 5.0 seconds to a final speed of 50m/s. Calculate the acceleration of the object