Average speed = total distance / total time
total distance = 40 + 20 = 60km
total time taken = 10 + 5 = 15 minutes
Average speed = 60/15 = 4km/min
Newton's law of universal gravitation states that a particle attracts every other particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers
I think the correct answer from the choices listed above is option C. The research of social psychologist vincent hsu determined that americans tend to fulfill their ideal of self-reliance through <span> developing personal ideals. Hope this answers the question.</span>