Calculate the amount of radiation of a black body at 400K temperature. `(sigma= 5.67 xx 10^-8 watt//m^2 //k^4)`

Calculate the force of gravitation between the earth and the Sun, given that the mass of the earth = 6 xx 10^24 kg and mass of the Sun = 2 xx 10^30kg . The average distance between the two is 1.5 xx 10^11 m .

A body which has surface area of 5.0 cm^2 and a temperature of 727 radiates 300j of energy per minute.What is its emissivity?( sigma=5.67*10^-8 W/m^-2 K^-4 )

Calculate the amount of energy neeeded to break a drop of water of diameter 2xx 10^-3 m into 10^9 droplets of equal size( Surface tension of water = 72xx 10^-31 N/m .

Calculate the energy of one mole of photons of radiations having wavelength 300 nm. (c=3xx10^(8) mS^(-1) , h= 6.626xx10^(-34)JS) .

What is the pressure inside the drop of mercury of radius 3.00 mm at room temperature? Surface tension of mercury at that temperature (20^@C) is 4.65 xx 10^-1 N m^-1 . The atmospheric pressure is 1.01 xx10^-5 Pa. Also give the excess pressure inside the drop.

Calculate the work done in blowing o soap bubble of radius 5 cm(surface tension of soap solution= 3xx10^-2 N/m).

For a decomposition reaction, the values of rate constants at two different temperatures are given below: K_1 = 2.15xx10^-8 Lmol^-1s^-1 at 650k K_2 = 2.39xx10^-7 Lmol^-1s^-1 at 700k Calculate the value of activation energy for the reaction (R = 8.314 JK^-1 mol^-1 )

In a cold climate water gets forzen causing damage to the radiator of a car. Ethylene glycol is used as an antifreezing agent for the purpose. Calculate the amount of ehtylene glycol to be added to 4kg of water to prevent it from freezing at -6^@C ( K_f for water = 1.85 K mol^(-1) kg)

Calculate the amount of work done for a wire which area of cross section 10^-6m^2 and length 1.5m to increase the length 4 xx 10^-3 m. Young's modules of elasticity 2 xx 10^(11N//m^2) .