Two identical cups containing the same volume of water at 45°C and 5°C, are left in a room at 25°C. Which of the following graphs correctly illustrates the variation of temperature with time?
A
B
C
D
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The correct answer is option A .while the 45 degrees water cools down to room temperature the 5 degrees water will heat up to room temperature, therefore the first graph is the answer pls correct this error
SORRY FOR THE INCONVENIENCE!!!!!!!
This is a Newton’s law of cooling/heating question.
Key ideas:
The room temperature is 25 °C.
Water at 45 °C will cool down toward 25 °C.
Water at 5 °C will warm up toward 25 °C.
In both cases, the temperature changes rapidly at first, then more slowly, and approaches 25 °C asymptotically (it does not cross or overshoot 25 °C).
The temperature–time graph should therefore be curved, not straight.
Checking the options:
A: One curve decreases from 45 °C to 25 °C, the other increases from 5 °C to 25 °C, both flattening with time ✔
B: Straight lines → unrealistic for heating/cooling ✘
C: Suggests overshooting or wrong final behavior ✘
D: Temperatures remain almost constant ✘
✅ Correct answer: A
they are supposed to maintain a constant temperature
heat lost by hot object=heat gained by cold object
until equilibrium is attained
option c clearly violates that as the temperature keeps changing even after equilibrium
