Chemical Engineering - Heat Transfer - Discussion
Discussion Forum : Heat Transfer - Section 1 (Q.No. 15)
15.
In Joule's experiment, an insulated container contains 20 kg of water initially at 25°C. It is stirred by an agitator, which is made to turn by a slowly falling body weighing 40 kg through a height of 4 m. The process is repeated 500 times. The acceleration due to gravity is 9.8 ms-2. Neglecting the heat capacity of agitator, the temperature of water (in °C) is
Discussion:
22 comments Page 2 of 3.
Hiren bhatt said:
7 years ago
Please explain in detail I'm not understanding this.
Arun said:
7 years ago
Thanks @Emeka.
RAJ KUMAR said:
8 years ago
Thermodynamics first law - energy conversation ( energy can not create and can not destroy but it convert one form to another form).
mgh = mS (t2-t1).
(500*40)*9.81*4 = (500*40+20)*4.2*(t2- 25).
t2= 34.4.
mgh = mS (t2-t1).
(500*40)*9.81*4 = (500*40+20)*4.2*(t2- 25).
t2= 34.4.
(1)
Amit said:
8 years ago
Basic Formula Used => n.m.g.h = m.cp.dt.
Shakti Singh said:
9 years ago
The formula is m*g*h = m*cp* (T1 - T2).
Emeka Udokwu said:
10 years ago
The potential energy of the falling body is converted to heat energy which will be gained by the water. The potential energy of the falling body is given by m*g*h = 40*9.81*4.
Since this is repeated 500 times, the total potential energy becomes 500*40*9.81*4 = m*cp (T1-T2). The mass of water and initial temperature is given and the heat capacity is known. Now solve for the unknown. Hope it's clearer @Yadav.
Since this is repeated 500 times, the total potential energy becomes 500*40*9.81*4 = m*cp (T1-T2). The mass of water and initial temperature is given and the heat capacity is known. Now solve for the unknown. Hope it's clearer @Yadav.
(1)
Yadav anil said:
10 years ago
Explain answer in detail.
Deepesh said:
1 decade ago
Means potential energy converted in to heat energy .4186 is the specific heat of water, Cp.
Sarang said:
1 decade ago
It is quite simple. In this we have to use first law of thermodynamics i.e. energy neither be created nor destroy it can converted from one form to another form and total quantity remain same.
And for this example refer the Joule's experiment's fig. Then you can understand it clearly.
And for this example refer the Joule's experiment's fig. Then you can understand it clearly.
Prageet kaushik said:
1 decade ago
Please elaborate a little bit on this answer. I am not able to understand. I got the point that heat lost = heat gained but nothing else.
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