11. which of the following phenomena is taking place when sound waves are reflected from a surface along parallel lines? a. refracting b. absorption c. focusing d. diffusion

The bar of prob. 5/82 is repeated here. the ends of the 0.4-m bar remain in contact with their re- spective support surfaces. end b has a velocity of 0.5 m/s and an acceleration of 0.3 m/s2 in the di- rections shown. determine the angular accelera- tion of the bar and the acceleration of end a.

Diverging mirrors and lenses always produce images

The three classes of rocks are sedimentary, metamorphic, and igneous. how are rocks classified into one of these three groups?