A toy elevator is raised from the ground floor to the second floor in 20 seconds. The power needed using 1000 J of work, is

i believe the answer would be:

d. violin, clarinet, french horn, and tuba

blue light is scattered in different directions by the tiny molecules of air. blue is scattered more than other colours because it has a shorter distance to travel which results in smaller waves. this is why we see a blue sky most of the time.