What do vertical and horizontal surface waves have in common?
- both waves travel along earth's surface and decrease in amplitude with depth below the surface.
- both waves travel within earth and increase in amplitude with depth below the surface.
- both waves travel along earth's surface and increase in amplitude with depth below the surface.
- both waves travel within earth and decrease in amplitude with depth below the surface.

Click the game tab at the bottom of the simulation and select level 1. (there is no seesaw balance for this part of the activity.) balance the first equation, and click check to see if you got it right. if you can’t balance it in the first try, you can try again. work through the five equations for level 1. click continue to go on to level 2, and later level 3. each level is more difficult than the one before. keep trying until all the equations are balanced. in one or two sentences, describe how you did in the balancing game. in a few more sentences, explain one strategy you learned for balancing more complex equations.