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An empty pressure cooker of volume 10 litres contain air at atmospheric pressure 10^5 Pa and temperature of 300 K. It contains a whistle which has area if 0.1 cm^2 and weight of 100 gm. What should be the Temprature of air inside so that the whistle is just lifted up?

An empty pressure cooker of volume 10 litres contain air at atmospheric pressure 10^5 Pa and temperature of 300 K. It contains a whistle which has area if 0.1 cm^2 and weight of 100 gm. What should be the Temprature of air inside so that the whistle is just lifted up?

Grade:12

2 Answers

Nishant Chandrashekar
18 Points
9 years ago

We can use P1/T1=P2/T2                      (where P1=Patm      T1=300k)

NOw to lift the weight a force needs to be applied on the weight which is greater than or equal to its weight

hence,F=mg     (where F is the minimum force required to lift the weight)

This force can be provided by the pressure (P2) inside the cooker

hence,

F=(P2)A  (where A is the area of cross section)

hence,

(P2)A=mg

find P2 from this and substitute in the first equation to get the answer 

Shuvam Shukla
37 Points
9 years ago

according to ur method P2 is 300k same as P1.. but the answer is 327K

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