Three children are playing in a pool in the back yard. one child is at the far left end of the pool and is splashing. a second child is laying on a float in the middle of the pool. the third child is at the far right of the pool and begins splashing as well. the child on the float in the middle of the pool notices that when both of her friends are splashing on opposite sides of the pool, she is raised much higher on her float as the waves lift her up. what phenomenon is the child in the middle of the pool experiencing?
a) doppler effect
b) seismic impact
c) destructive interference
d) constructive interference

The answer is; D

When both kids splash at both ends of the pool, the waves formed from the different direction travel and meet in the middle of the pool (since they are traveling with the same speed). When the waves meet, they interact and form constructive waves. This means that when a crest meets a crest, the height doubles. This also occurs for the troughs. Therefore the sizes of the waves at the middle are twice the individual waves.

> b takes place in the gas phase in an isothermal tubular reactor. the feed is one mole of a per one mole of c, an inert. the entering temperature and pressure are 427°c and 10 atm, respectively. the gas constant r = 0.08206 atm · l/mol · k.