A sound wave passes from air into water and then into steel. With each change in medium, what happens to the speed of the wave?
А
It increases
B
It decreases. C
It increases then decreases
D
It decreases then increases

You are driving directly behind a pickup truck, going at the same speed as the truck. a crate falls from the bed of the truck to the road. (a) will your car hit the crate before the crate hits the road if you neither brake nor swerve? (b) during the fall, is the horizontal speed of the crate more than, less than, or the same as that of the truck?