True false question
1. refraction occurs because waves change speed in a new medium. (true/false)
short answer questions
fill in the answer blanks with the correct answer.
3.
2. an echo is an example of the type of wave interaction called
fill in the blanks questions
fill in the answer blanks with the correct answer.
is the bending of waves when they enter a new medium at an angle.
occurs when waves spread out and travel around obstacles or
through openings in obstacles.
is the bouncing back of waves from a surface that they cannot pass
5.
through

A23 kg log of wood begins from rest, 300 m up a sluice (a water track used to transport logs, think of it as an inclined plane with negligible friction) inclined at 20° to the horizontal. after it reaches the flat waterway at the bottom it collides elastically with a 100 kg block of wood initially at rest near the base of the incline. (a) how long does it take the 23 kg log to travel down the incline? (b) what is the speed of the 23 kg log at the bottom of the incline? (c) what are the velocities of both blocks of wood after the collision? (d) what is the total kinetic energy before the collision? (e) what is the kinetic energy of the 23 kg log after the collision? (f) what is the kinetic energy of the 100 kg block of wood after the collision? (g) what is the total kinetic energy after the collision? (h) compare the total initial and total final kinetic energies. is this consistent with what you would expect for elastic collisions? explain!

Two carts, one of mass 2m and one of mass m, approach each other with the same speed, v. when the carts collide, they hook together. assume that positive momentum is to the right. which graph best represents the momentum of both carts over time, before and after the collision?

Acid precipitation chemically weathering a 5.0-kg limestone rock . which coukd be the result ?