Home
Class 11
PHYSICS
Two solid copper spheres of radii r1=15c...

Two solid copper spheres of radii `r_1=15cm` and `r_2=20cm` are both at a temperature of `60^@`C. If the temperature of surrounding is `50^@C`, then find
a. The ratio of the heat loss per second from their surfaces initially.
b. the ratio of rates of cooling initially.

Text Solution

AI Generated Solution

To solve the problem, we will break it down into two parts as specified in the question. ### Part (a): The ratio of the heat loss per second from their surfaces initially. 1. **Understanding Heat Loss**: According to Newton's law of cooling, the rate of heat loss (dQ/dt) from a body is proportional to the surface area and the temperature difference between the body and its surroundings. \[ ...
Promotional Banner

Topper's Solved these Questions

  • CALORIMETRY

    CENGAGE PHYSICS ENGLISH|Exercise Exercise 1.1|23 Videos

  • CALORIMETRY

    CENGAGE PHYSICS ENGLISH|Exercise Exercise 1.2|22 Videos

  • BASIC MATHEMATICS

    CENGAGE PHYSICS ENGLISH|Exercise Exercise 2.6|20 Videos

  • CENTRE OF MASS

    CENGAGE PHYSICS ENGLISH|Exercise INTEGER_TYPE|1 Videos

Similar Questions

Explore conceptually related problems

Two uniform solid spheres made of copper have radii 15 cm and 20 cm respectively. Both of them are heated to a temperature of 70^(@)C and then placed in a region of ambient temperature equal to 45^(@)C . What will be the ratio of the initial rates of cooling of both the spheres?

Two identical spheres A and B are suspended in an air chamber which is maintained at a temperature of 50^@C . Find the ratio of the heat lost per second from the surface of the spheres if a. A and B are at temperatures 60^@C and 55^@C , respectively. b. A and B are at temperatures 250^@C and 200^@C , respectively.

Two spheres of same material and radius r and 2r are heated to same temperature and are kept in identical surroundings, ratio of their rate of loss of heat is

The sphere of radii 8 cm and 2 cm are cooling. Their temperatures are 127^(@)C and 527^(@)C respectively . Find the ratio of energy radiated by them in the same time

Consider two hot bodies B_(1) and B_(2) which have temperature 100^(@)"C" and 80^(@)"C" respectively at t = 0. The temperature of surroundings is 40^(@)" C" . The ratio of the respective rates of cooling R_(1) and R_(2) of these two bodies at t = 0 will be

Two conducting spheres of radii R_(1) and R_(2) are at the same potential. The electric intensities on their surfaces are in the ratio of

Two solid spheres of radii R_(1) and R_(2) are made of the same material and have similar surfaces. These are raised to the same temperature and then allowed to cool under identical conditions. The ratio of their initial rates of loss of heat are

Thickness of ice on a lake is 5 cm and the temperature of air is -20^(@)C . If the rate of cooling of water inside the lake be 20000 cal min^(-1) through each square metre surface , find K for ice .

A solid aluminium sphere and a solid copper sphere of twice the radius are heated to the same temperature and are allowed to cool under identical surrounding temperatures. Assume that the emisssivity of both the spheres is the same. Find ratio of (a) the rate of heat loss from the aluminium sphere to the rate of heat loss from the copper sphere and (b) the rate of fall of temperature of the aluminium sphere to the rate of fall of temperature of copper sphere. The specific heat capacity of aluminium =900Jkg^(-1)C^(-1) . and that of copper =390Jkg^(-1)C^(-1) . The density of copper =3.4 times the density of aluminium.

Two solid spheres A and B made of the same material have radii r_(A) and r_(B) respectively . Both the spheres are cooled from the same temperature under the conditions valid for Newton's law of cooling . The ratio of the rate of change of temperature of A and B is