Water gained heat at the rate of 12° Celsius per minute for 5 minutes. It was then allowed to lose heat at 4° Celsius per minute. If the temperature before heating was 22° Celsius, what was its temperature after 8 1/2 minutes?
start: 22°
increase for 5 min: 5(12) = 60°
temp after 5 min = 22+60 = 82°
decrease for next 3.5 min = 3.5(4) = 14°
so temp after 8.5 minutes = 82-14 = 68°
Where does 3.5minutes come from
i did not understand the working since it was low explanation
22% 5(12)=60 after 5 minutes
To solve this problem, we need to consider the heating and cooling processes separately and then combine their effects.
Let's break down the problem step by step:
1. Heating: The water gains heat at a rate of 12° Celsius per minute for 5 minutes.
- Since the temperature was initially 22° Celsius, we can calculate the temperature after 5 minutes of heating:
Temperature after 5 minutes of heating = Initial temperature + (Rate of heating x Time)
Temperature after 5 minutes of heating = 22 + (12 x 5) = 22 + 60 = 82° Celsius
2. Cooling: After 5 minutes of heating, the water begins to lose heat at a rate of 4° Celsius per minute.
- We need to find the temperature after 8.5 minutes, so we need to calculate the cooling effect for the remaining 3.5 minutes.
- Cooling effect = Rate of cooling x Time = 4 x 3.5 = 14° Celsius
Now, we can combine the effects of heating and cooling to find the final temperature:
Final temperature = Temperature after heating - Cooling effect
Final temperature = 82 - 14 = 68° Celsius
Therefore, the water's temperature after 8 1/2 minutes is 68° Celsius.