If the initial temperatures of metallic sphere and disc, of the same mass, radius and nature are equal, then the ratio of their rate of cooling in same environment will be

A solid cylinder and a sphere of same material are suspended in a room turn by turn, after heating them to the same temperature. The cylinder and the sphere have same radius and same surface area. (a) Find the ratio of initial rate of cooling of the sphere to that of the cylinder. (b) Will the ratio change if both the sphere and the cylinder are painted with a thin layer of lamp black?

The side of a cube is equal to the diameter of a sphere. If the side and radius increase at the same rate then the ratio of the increase of their surfaces is

'A' solid sphere and solid disc having the same mass and radius roll down on the same inclined plane. What is the ratio of their accelerations ?

A metallic solid sphere and a hollow sphere of same material and external radius are heated to the same temperature and allowed to cool in the same environment .Which of the two has aa greater cooling rate?

Assertion : A solid sphere of copper of radius R and a hollow sphere of the same material of inner radius r and outer radius R are heated to the same temperature and allowed to cool in the same environment. The hollow sphere cools faster. Reason : Rate of cooling is according to Stefan's law which is E alpha T^(4)

A solid sphere of copper of radius R and a hollow sphere of the same materail of inner radius r and outer radius A are heated to the same temperature and allowed to cool in the same environment. Which of tehm starts cooling faster?

"A solid sphere of copper of radius R and a hollow sphere of the same material of inner radius r and outer radius R are heated to the same temperature and allowed to cool in the same environment. Which of them starts cooling faster ?''

Two metallic spheres A and B are made up of same material and also have identical surfaces. Both spheres are heated to same temperature and are then placed in a chamber which is at a lower temperature, thermally insulated from each other. If ratio of masses of A and B is 3:1, then the ratio of their initial rate of cooling is