When you wrap a sandwich in plastic food wrap to protect it. you must first unroll the plastic wrap from the container and then wrap the plastic around the sandwich. In both steps. You encounter friction. In each step is friction helplul or not? Explain your answer

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