A Lamborghini Diablo accelerates at 10 m/s$$ , and goes from a speed of 0 m/s to 40 m/s. How long did it take the Lamborghini to reach its final speed?

a and b sometimes have a positive value

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.