The doctor took the temperature of a dead body at 11.30 Pm which was `94. 6^@F`. He took the temperature of the body again after one hour, which was `93. 4^@F`. If the temperature of the room was `70^@F` , estimate the time of death. Taking normal temperature of human body as `98. 6^@F`. [Given: `log(143/123)=0. 15066 ,log(123/117)=0. 05` ]

A body at a temperature of 50^0F is placed outdoors where the temperature is 100^0F . If the rate of change of the temperature of a body is proportional to the temperature difference between the body and its surrounding medium. If after 5 min the temperature of the body is 60^0F , find (a) how long it will take the body to reach a temperature of 75 ^0 F and (b) the temperature of the body after 20 min.

Imagine a system, that can keep the room temperature within a narrow range between 20^@C to 25^@C . The system includes a heat engine operating with variable power P = 3KT, where K is a constant coefficient, depending upon the thermal insulation of the room, the area of the walls and the thickness of the walls. T is temperature of the room in temperature drops lower than 20^@C , the engine turns on, when the temperature increase over 25^@ C, the engine turns off, room looses energy at a rate of K(T - T_0), T_0 is the outdoor temperature. The heat capacity of the room is C. Given (T_0=10^@C, ln(3/2) =0.4 , ln(6/5)=0.18 , C/K =750 SI-unit) Suppose at t = 0, the engine turns off, after how much time interval, again, the engine will turn on

Imagine a system, that can keep the room temperature within a narrow range between 20^@C to 25^@C . The system includes a heat engine operating with variable power P = 3KT, where K is a constant coefficient, depending upon the thermal insulation of the room, the area of the walls and the thickness of the walls. T is temperature of the room in temperature drops lower than 20^@C , the engine turns on, when the temperature increase over 25^@ C, the engine turns off, room looses energy at a rate of K(T - T_0), T_0 is the outdoor temperature. The heat capacity of the room is C. Given (T_0=10^@C, ln(3/2) =0.4 , ln(6/5)=0.18 , C/K =750 SI-unit) Suppose at t = 0, the engine turns on, after how much time interval again, the engine will turn off

Newton's law of cooling states that the rate of change of the temperature T of an object is proportional to the difference between T and the (constant) temperature tau of the surrounding medium, we can write it as (dT)/(dt) = -k(T - tau) k gt 0 constant An cup of coffee is served at 185^(@)F in a room where the temperature is 65^(@)F . 2 minutes later the temperature of the coffee has dropped to 155^(@)F . log_(e)3 = 1.09872, log_(e).(3)/(4) = 0.2877 Time required for coffee to have 105^(@)F temperature is

Newton's law of cooling states that the rate of change of the temperature T of an object is proportional to the difference between T and the (constant) temperature tau of the surrounding medium, we can write it as (dT)/(dt) = -k(T - tau) k gt 0 constant An cup of coffee is served at 185^(@)F in a room where the temperature is 65^(@)F . 2 minutes later the temperature of the coffee has dropped to 155^(@)F . log_(e)3 = 1.09872, log_(e).(3)/(4) = 0.2877 Temperature of coffee at time t is given by

The human body has an average temperature of 98^(@)F . Assume that vapor pressure of the blood in the veins behaves like that of pure water. Find the minimum atmospheric pressure which is necessary to prevent the blood from boiling. Use figure for the vapor pressures.

The normal body-temperature of a person is 97^(@)F . Calculate the rate at which heat is flowing out of his body through the clothes assuming the following values. Room temperature =47^(@)F , surface of the body under clothes =1.6m^(2) , conductivity of the cloth =0.04Js^(-1)m^(-1)C^(-1) , thickness of the cloth =0.5cm .

A child running a temperature of 101^F is given and antipyrin (i.e. a madicine that lowers fever) which cause an increase in the rate of evaporation of sweat from his body. If the fever is brought down to 98^@F in 20 min., what is the averatge rate of extra evaporation caused, by the drug ? Assume the evaporation mechanism to the only way by which heat is lost. The mass of the child is 30 kg. The specific heat of human body is approximately the same as that of water and latent heat of evaporation of water at that temperature is about 580 cal. g^(-1).

A concentration cell Pt|H_2(g)|HCl(aq)||H_2SO_(4)(aq)|H_2(g)|Pt is constructed using equal concentration of acids and equal number of moles of H_2 gas in both the compartments at the same temperature.If volume of H_2 gas at the anodic compartment is 1/9 times the volume of H_2 gas at cathodic compartment Which of the following is/are correct for the given cell (log 2=0.3, log 3=0.48)(2.303 RT)/F=0.06 V

(i) A conducting cylinder whose inside diameter is 4.00cm contains air compressed by a piston of mass m = 13.0 kg , which can slides freely in the cylinder shown in the figure. The entire arrangement is immersed in a water bath whose temperature can be controlled. The syetem is initially in equilibrium at temperature t_(1) = 20^(@)C . The initial height of the piston above the bottom of the cylinder is h_(i) = 4.00 cm. P_(atm) =1 xx 10^(5) N/m^(2) and g = 10m//s^(2) . If the temperature of the water bath is gradually increased to a final temperature t_(f) = 100^(@)C . Find teh height h_(f) of the piston (in cm) at that instant? (ii) In the above question, if we again start from the initial conditions and the temperature is again gradually raised, and weights are added to the piston to keep its height fixed at h_(i) . Find the value of teh added mass when the final temperature becomes t_(f) = 100^(@)C ?