Suppose a human could live for two hours (120 minutes ) unclothes in a

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SUMMARY

A human can survive for 120 minutes (2 hours) unclothed in air at 45°F. The thermal conductivity of air is 0.0251 W/m°C, while that of water is 0.597 W/m°C. Using the formula for conduction, the time a human could survive in water at the same temperature is calculated to be approximately 5.04 minutes. This calculation corrects earlier errors in the thermal conduction formula application.

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Suppose a human could live for two hours (120 minutes ) unclothes in air at 45 F . How long could he live in water at 45 F ?

how do the thermal conductivities of water and air compare ?
Air : k = 0.0251 W/mC ,
water = k = 0.597 W/mC


my answer

now for conduction we will say that

-k(air ) .A(dT/dx) dtime = -k(water ) .A(dT/dx) dtw

= 0.025 X 2 / 0.597

= 0.083 second
 
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manal950 said:
= 0.025 X 2 / 0.597

= 0.083 second

Huh?

No idea what is what of what nor how you got the number you got.

What is 2?

And your math is incredibly off.
 
sorry

= 0.025 X 120 / 0.597

= 5.04
 
That looks much more palatable.

It won't hurt to include units in your answer.
 

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