when lightning strikes you can see it at a speed of 3x10^8m/s. But you hear thunder at about 340m/s in 70 degrees air temperature. a) If you are a mile away from lightning, how long of a delay is there?
b) if the delay between the lightning and thunder were 1s how far away would you be in km and in miles?
a) I used d=d_0+v_0t+1/2at^2
which becomes d=v_0t
1609.34=340t
t=4.73s
b) d=v_0t
d=3x10^8 m/s(1s)
d=3x10^8m
=18641.14mi
=300,000 km
But this doesn't make any sense. Did i do something wrong?
In part b you used the speed of light for Vo but its the speed of sound that determines how long it takes to hear it.
No, you did not do anything wrong. The calculations you performed are correct. However, the result might seem a bit confusing because of the units.
In part a), when you calculated the delay between seeing the lightning and hearing the thunder, you correctly found that it takes approximately 4.73 seconds for the sound to travel 1 mile at a speed of 340 m/s. This means there is a delay of 4.73 seconds between seeing the lightning and hearing the thunder when you are a mile away.
In part b), when you calculated the distance between the lightning and yourself given a delay of 1 second, you used the speed of sound (340 m/s) to calculate the distance traveled by the sound in 1 second. You correctly found that 340 m/s * 1 s = 340 m.
However, the confusion might arise when converting this distance to kilometers and miles. 340 meters is approximately 0.34 kilometers (since there are 1000 meters in a kilometer) and approximately 0.21 miles (since there are approximately 1609 meters in a mile). Therefore, if there is a delay of 1 second between seeing the lightning and hearing the thunder, you would be approximately 0.34 kilometers or 0.21 miles away from the lightning.
So, your calculations are correct, but please double-check the unit conversions when converting between meters, kilometers, and miles to avoid any confusion.