A certain freezing process requires that room temperature be lowered from ${40}^{\circ }C$ at the rate of $5^{\circ }C$ every hour. What will be the room temprature 10 hours after the process begins ?

A certain freezing process requires that room temperature be lowered from ${40}^{\circ }$ C at the rate of $5^{\circ }$C per hour. What will be the room temperature $12$ hours after the process begins?

6).A certain freezing process requires that room temperature be lowered from 40oC at therate of 5oC every hour. What will be the room temperature 10 hours after the processbegins?(7). In a class test containing 10 questions, 5 marks are awarded for every correct answer and $(-2)$ marks are awarded for every incorrect answer and 0 for questions not attempted. (i) Mohan gets four correct and six incorrect answers. What is his score? (ii) Reshma gets five correct answers and five incorrect answers, what is her score? (iii) Heena gets two correct and five incorrect answers out of seven questions she attempts. What is her score?

A certain freezing process requires that room temperature be lowered from 50°C at the rate of 4°C every hour. What will be the room temperature 18 hours after the process begins ?

Water is filled in a vessel which is kept in a room at a temperature of ${20}^{\circ }C$. The temperature of the water is slowly increased. When the temperature of water is ${40}^{\circ }C$, it loses heat at the rate of 10cal/s. What will be the rate of loss of heat when the temperature of water is ${80}^{\circ }C$ ?

In the morning the temperature of Delhi was ${29}^{\circ }C$. After 3 hours it was $4^{\circ }$C warmer. What was the temperature at that time?

The count rate of a radioactive sample falls from $4.0\times {10}^6{s}^{-1}$ to $1.0\times {10}^6{s}^{-1}$ in 20 hours. What will be the count rate after 100 hours from beginning ?

Imagine a system, that can keep the room temperature within a narrow range between ${20}^{\circ }C$ to ${25}^{\circ }C$. 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 ${20}^{\circ }C$, the engine turns on, when the temperature increase over ${25}^{\circ }$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 $(T_0={10}^{\circ }C,\ln \left(\frac{3}{2}\right)=0.4,\ln \left(\frac{6}{5}\right)=0.18,\frac{C}{K}$=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 ${20}^{\circ }C$ to ${25}^{\circ }C$. 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 ${20}^{\circ }C$, the engine turns on, when the temperature increase over ${25}^{\circ }$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 $(T_0={10}^{\circ }C,\ln \left(\frac{3}{2}\right)=0.4,\ln \left(\frac{6}{5}\right)=0.18,\frac{C}{K}$=750 SI-unit)
Suppose at t = 0, the engine turns on, after how much time interval again, the engine will turn off

Liquid is filled in a vessel which is kept in a room with temperature 20°C. When the temperature of the liquid is 80°C, then it loses heat at the rate of 60 cal/sec. What will be the rate of loss of heat when the temperature of the liquid is 40°C ?

For a certain gaseous reaction rise of temperature from ${25}^{\circ }C$ to ${35}^{\circ }C$ doubles the rate of reaction. What is the value of activation energy :-