5. The diagram below shows a toy cart possessing 16 joules of kinetic energy traveling on a frictionless, horizontal surface toward a horizontal spring. If the cart comes to rest after compressing the spring a distance of 1.0 meter, what is
the spring constant of the spring?

explanation:

as the height from which the ruler was dropped increased, the speed of the ruler at ryan's hand increased.

that would be because of both gravity and friction. so     c

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.