A certain freezing process requires that room temperature be lowered from $40^{\circ}\ C$ at the rate of $5^{\circ}\ C$ every hour. What will be the room temperature 10 hours after the process begins?

AcademicMathematicsNCERTClass 7

Given :

Initial Room temperature $= 40^o\ C$.

Rate of decrease of temperature $=5^o\ C$ per hour.

To do:

We have to find the room temperature after 10 hours.

Solution :

Temperature decreased in 1 hour $= 5^o\ C$

Temperature decreased in 10 hours $= 10 \times 5^o\ C$

$= 50^o\ C$


The temperature of the room after 10 hours $=$ Initial temperature $-$ Decrease in temperature

$= 40^o\ C - 50^o\ C$

$= -(50-40)^o\ C$

$= -10^o\ C$.

Therefore, the room temperature after 10 hours will be $-10^o\ C$.

Updated on 10-Oct-2022 13:31:02