Seven seconds after a brilliant flash of lightning, thundershakes the house. How far was the lightning strike from thehouse?

a. much closer than 1 kilometer

b. about 1 kilometer away

c. about 2 kilometers away

d. much farther than 2 kilometers

Seven seconds after a brilliant flash of lightning, thunder shakes the house.

The lightning strike was about 2 kilometers away. (c)

The speed of sound is roughly 340 m/s. So in 7 seconds, the sound of the thunder would have traveled roughly 2,380 meters from the location of the strike. But in the tangled mess of warm air, cold air, and rain surrounding a thunderstorm, the sound doesn't travel a straight line, so the actual location of the lightning was a little closer to the house than the total distance that the sound traveled. "About 2 kilometers" is a reasonable estimate.