A boy claps his hand when he is 420m from the bottom of the cliff. he heard the eco after 2.4 second. what is the speed of sound

350 m/s

Explanation:

In order for Boy to hear the sound, the sound  has to travel from his hands to the cliff, and then BACK to him from the cliff to his ears.

So the sound has to travel (2 x 420m) = 840 m.

Speed = (distance) / (time)

Speed = (840 m) / (2.4 sec)

Speed = 350 m/s

350 m/s

Explanation:

with the invention of the automobile, the woman of the house could drive to the store and get groceries. women were also free to socialize more. during world war ii women were allowed to work in factories to the war effort and could drive to work or ride mass transit buses to their jobs.