The windchill factor is a measure of the cooling effect that the wind has on a person’s skin. It calculates the equivalent cooling temperature if there were no wind. The National Weather Service uses the formula

Windchill temperature = 35.74 + 0.6215T - 35.75V^4/25 + 0.4275TV^4/25,

where T is the temperature in °F and V is the wind speed in miles per hour, to calculate windchill. The table gives the windchill factor for various wind speeds and temperatures at which frostbite is a risk, and how quickly it may occur.

Use the formula to determine the windchill temperature to the nearest tenth of a degree, given the following conditions. Compare answers with the appropriate entries in the table.

10°F, 30-mph wind

Transcribed Image Text:

Calm 40 Wind speed (mph) 20 13 9 6 1978 4 3 1 0 -1 30 5 36 25 10 34 21 15 32 20 30 25 29 30 28 35 28 40 27 16 17 16 15 14 13 Temperature (°F) 10 0 -10 -20 -30 -40 1 -11 -22 -34 -46 -57 -4 -16 -28 -41 -53 -66 -7 -19 -32 -45 -58 -9 -22 -35 -48 -61 -11 -24 -37 -51 -64 -12 -26 -39 -53 -67 -14 -27 -41 -55 -69 -15 -29 -43 -71 -74 -78 -80 -82 -57 -71 -84 Frostbites times: 30 minutes 10 minutes 5 minutes Data from National Oceanic and Atmospheric Administration, National Weather Service.