Lightning striking distance

Figure 12. Lightning strike to house and conductor showing distance to interior...

Seek safe shelter. Lightning can strike as far as 10 miles from the area where it is raining. That s also about the distance you can hear thunder. Remember that if you can hear thunder, you are within striking distance. Seek safe shelter immediately. 

To arrive at this striking conclusion, let s do an order-of-magnitude calculation. Suppose that the phase point lies off the curve C. For instance, suppose (0, 1) lies an 0(1) distance below the curve C, i.e, Q < f < > ) and /(0) - O = 0(1). Then (8b) shows that Q is enormously positive Q Oiy/E) 1. Thus the phase point zaps like lightning up to the region where /(0) - Q = 0( ). In the limit -> 0, this region is indistinguishable from C. Once the phase point is on C, it evolves according to Q f ) , that is, it approximately satisfies the first-order equation < = /(0)-... 

Counting the seconds between a flash of lightning and the clap of thunder is often used to estimate how far away the lightning struck. If sound travels at a speed of 330 m/s, what is the time delay between lightning and thunder for lightning that strikes at a distance of 1.0 mile ... 

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