A boy of mass 50 kg is standing on a weighing machine placed on the floor of a lift. The machine reads his weight in newton. What is the reading of the machine when the lift is stationary? Take g=9.8 ms−2
There are 50 students in a class, of which 40 are boys. The average weight of the class is 44 kg and that of girls is 40 kg. Find the average weight of the boys.