Which class of lever will always have M.A. > 1 and why?

Define heat capacity and state it's S.I. unit.

A solid of mass 50 g at 150°C is placed in 100 g of water at 11°C, when the final temperature recorded is 20°C. Find the specific heat capacity of the solid. (Specific heat capacity of water = 4.2 J/g°C).

How is the refractive index of a material related to?

(i) real and apparent depth?

(ii) velocity of light in vacuum or air and the velocity of light in a given medium?