Diameter of a planet is ` 10d_(@)`, its mean density is `(rho_(@))/(4)` and mass of its atmosphere is ` 10m_(@)` where `d^(@)`, `rho^(@)` and `m^(@)` are diameter, mean density and mass of atmosphere respectively for the earth. Assume that mean density of atmosphere is same on the planet and the earth and height of atmosphere on both the planets is very small compared to their radius. Find the ratio of atmospheric pressure on the surface of the planet to that on the earth. If a mercury barometer reads 76 cm on the surface of the earth, find its reading on the surface of the planet.

Answer

(a) ` 5/2`
(b) 7.6cm