The distance between boy and a hill is 250 metres. If the boy shouts, after how long will the echo be heard?

In a given chemical reaction, the energy of the products is greater than the energy of the reactants. which statement is true for this reaction?

What is the momentum of a 2 kg object moving at 15 meters per second

You want to lose weight and have been trying to decide which type of fad diet is best for you. you ask your doctor, who responds that a. fad diets are a temporary fix but generally don't have any side effects b. fad diets can be used several times a year to maintain a healthy weight c. fad diets can be risky for your health and, in the long run, do not work d. fad diets should never be used one right after the other; there should be a break between them select the best answer from the choices provided. a b c d