Suppose we use a physical balance to measure the mass of an object and find the mean value of our observation to be 156.28 g . If the least count of the balance is 0.1 g . how should the result be reported ?

A physical quantity P is related to four observables a, b, c and d as follows: P = (a^(3)b^(3))/(sqrt(cd)) The percentage errors of measurement in a,b, c and d are 1%, 3%, 4%, and 2% respectively. What is the percentage error in the quantity P? If the value of P calculated using the given relation turns out to be 3.763, to what value should the result be rounded off?

From the two arms of a beam balance, a metal body weighing 20 g and a piece of glass are suspended. The apparent weights of these two bodies when measured in water are found to be the same. If immersed in alcohol instead of water, the mass of the metal needs to be increased by 0.84 g for balancing the beam. Calculate the mass of the glass piece. [Given, density of water = 1g*cm^(-3) , density of alcohol = 0.96g*cm^(-3) ]

Mass of a body determined by an analytical balance (accuracy 0.0001g) was reported to be 10.0008g. Find the no. of significant figures in reported mass.

A body of mass 100 g is heated up to 122^(@)C and dropped quickly in water of mass 300 g kept at 28^(@)C in a copper calorimeter of mass 50 g. The final temperature of the mixture becomes 30^(@)C. If the specific heat of copper is "0.09 cal.g"^(-1).^(@)C^(-1) , find the specific heat of the material of the body.

10^(18) electrons hit a target per second in a X-ray tube with a velocity of 2 xx 10^(6) m cdot s^(-1) . The mass of the metallic piece of the target is 200 g, specific heat is 0.12 cal cdot g^(-1) cdot^(@)C^(-1) and mass of an electron is 9.1 xx 10^(-28) g . If 98% of the energy is converted into heat, how much time will be required to increase the temperature of the metallic piece of the target by 50^(@)C ?

A closed container of volume 0.02 m^3 contains a mixture of neon and argon gases at a temperature of 27^@C and pressure of 1 times 10^5 N.m^-2 The total mass of the mixture is 28 g. IF the molar masses of neon and argon are20 and 40 g//mol respectively . find the masses of the individual gases in the container assuming then to be ideal. [R=8.314 J.mol^-1.K^-1 ]

In a constant volume calorimeter, 3.5g of a gas with molecular mass 28 was burnt in excess oxygen at 298.0 K. the temperature of the calorimeter was found to increase from 298.0K to 298.45K, due to the combustion process. Given, that the heat capacity of the calorimeter is 2.5kJ*K^(-1) , what will be the value of enthalpy of combustion of the gas?