# Thermometer Reading

## Differential equations: Newton's Law of Coolin

Need help on this..DE Newton's Law of Cooling

A thermometer is removed from a room whose ambient temperature is 70° F and is taken outside.

After one minute the thermometer reads 60° F and after three minutes, it reads 55° F. **What is the outside
temperature (which is assumed to be constant)**? Find your answer by solving DE model of Newton’s Law

of cooling.

## Differential equations: Newton's Law of Cooling

Need help on this one. DE Newton's Law of Cooling

At 9 A.M., a thermometer reading 70°F is taken outdoors where the temperature is

l 5°F. At 9: 05 A.M., the thermometer reading is 45°F. At 9: 10 A.M., the thermometer is

taken back indoors where the temperature is fixed at 70°F. Find (a) the reading at

9: 20 A.M. and (b) when the reading, to the nearest degree, will show the correct

(70°F) indoor temperature.

## Differential Equation: Thermometer reading

At 1:00pm., a thermometer reading 70F is taken outside where the air temperature is -10F (ten below zero). At 1:02pm., the reading is 26F. At 1:05pm., the thermometer is taken back indoors, where the air is at 70F. What is the temperature reading at 1:09pm?