What is the average speed of sound in air at sea level?

May someone explain how to do this question?

Jessie ran 5000 meters from the cops and an average speed of 6 meters / second before he got caught . how long did he run?

When considering gravity acceleration and the force of acceleration, what must be true? a. the direction of acceleration must be perpendicular to the direction of the force. b. the direction of the force and the direction of acceleration must be the same as each other. c. the direction of the force and the direction of acceleration must be opposite of each other. d. the mass of the body must be the same as the acceleration of the body.