Question

A thermometer is taken from a room where the temperature is 18oC to the outdoors, where the temperature is −4oC. After one minute the thermometer reads 7oC. (a) What will the reading on the thermometer be after 4 more minutes? , (b) When will the thermometer read −3oC? minutes after it was taken to the outdoors?

Answer 1

(a) -37°C

(b) 1
`(10)/(11)`minutes≈1.91 minutes

Explanation:

(a) The thermometer reading was 18°C in a room and this dropped to a reading of 7°C outdoor after 1 minute hence in 1 minute, temperature (heat) loss

=
`18-7`

=
`11`°C

After 4 more minutes, the thermometer would have lost additional 44 minutes (4×11). Hence thermometer reading after 4 more minutes would be

=1
`(10)/(11)` minutes

≈1.91 minutes