Keshav observed that the increase in the temperature of a body is given by `T_(1) = 2t^(2)` for the first 5 minutes and `T_(2)` = 3t for the next 5 minutes, where `T_(1)`, `T_(2)` and 't' are temperatures in Fahrenheit, Celsius scales and time in minutes, respectively. If the initial temperature of the body is `20^(@)F` and the relation between the Celsius and Fahrenheit scale is, then find the temperature of the body after 8 minutes in Celsius scale.

Answer

`30^@C`

Explanation

For 1st 5 minutes
`T_(1)=2t^2`
`=2xx25`
`=50^@F`
Initial temperature = 20°F
After 5 min = 20° + 50° = 70°F
`C/5=(F-32)/9`
`C=(70-32)/9xx5`
`=21^@C`
Increase in temperature after next 3 minutes
`T_(2)=3t`
`=3xx3`
`T_(2)=9`
`rArr` Increase in temperature is 9°C
Temperature after 8 minutes
`=21+9`
`=30^@C`