Two loudspeakers, a and b, are driven by the same amplifier and emit sinusoidal waves in phase. the frequency of the waves emitted by each speaker is 172 hz. you are 8.00 m from speaker a. take the speed of sound in air to be 344 m/s. part a what is the closest you can be to speaker b and be at a point of perfectly destructive interference? express your answer in meters.

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."

statement #3 on andre"s list is false.

the best answer for these questions would be:

1.            c. is smaller

2.            d) concrete operational

3.            b) interaction with the environment – the children interact with their environment can them learn more.

4.            a) parents who reason openly with children can limit a child’s cognitive ability.