two waves on a string have the following wave functions: 3x 4t- where y, and x are measured in cm, and t is measured in seconds. a. at what time do the two waves completely cancel each other? b. at what position on the string is the total disturbance always zero? c. show that these two waves satisfy the 1-d wave equation.

the first american roller coaster was the mauch chunk switchback railway, built in the mountains of pennsylvania in the mid-1800s. the track, originally built to send coal to a railway, was reconfigured as a "scenic tour."

electrical power

the five characteristics of adolescence are biological growth and development, and undefined status, increased decision making, increased pressure and the search of self.

causes

fossil fuels burn

cities become more industrialized

human population grows worldwide