Answer:
3.2 miles
Explanation:
We can assume that the light coming from the lightning reach instantaneously our eyes (because light travels very fast, 
), so the time between the lightining and the hearing of the thunder is equal to the time that sound takes to each us.
Sound travels in air approximately at speed
v = 343 m/s
So the distance it covers in a time of t = 15 seconds is
And using the conversion from meters to miles,
1 mile = 1609 meters
we find
Destructive Interference. An example of destructive interference is noise canceling headphones. Noise canceling headphones work by using a microphone to pick up the frequencies of incoming waves. The headphone then sends out a wave that is the exact opposite, canceling out the sound.
Answer:
Explanation:
In a velocity/time (aka acceleration) graph, the slope of a line indicates the value of the acceleration in m/s/s. Acceleration is the change in velocity over the change in time. From 0 - 2 seconds, there is no change in velocity, so the acceleration during this interval is 0 (which is the same as the slope of the line). From 2 - 4 seconds, the slope of the line is -2, so the acceleration during the time interval from 2 to 4 seconds is -2 (negative because David is slowing down but is still going the same direction: to the right).
