An object of density 12g*cm^(-3) is weighed with some counterpoising weights made of brass with the help of a common balance. Density of brass = 8g*cm^(-3). If the buoyancy of air is neglected in this measurement of mass. Density of air = 1.2xx10^(-3)g*cm^(-3).

An object of density 12g*cm^(-3) is weighed with some counterpoising w

1.	An object of density 12gcm^(-3) is weighed with some counterpoising weights made of brass with the help of a common balance. Density of brass = 8gcm^(-3). If the buoyancy of air is neglected in this measurement of mass. Density of air = 1.2xx10^(-3)g*cm^(-3).
Answer» Solution :LET the real WEIGHT of the body be `mgxxg`, real weight of the BRASS weights = m. `gxxg`. Here, apparent weight of the body = apparent weight of the brass weights or, real weight of the body - weight of air DISPLACED by the body = real weight of the brass weights or, `m-m/12xx1.2xx10^(-3)=m.-(m.)/8xx1.2xx10^(-3)` or, `m-mxx10^(-4)=m.-m.xx1.5xx10^(-4)` or, `(m.)/m=(1-10^(-4))/(1-1.5xx10^(-4))` or, `(m.-m)/m=((1.5-1)xx10^(-4))/(1-1.5xx10^(-4))=0.5xx10^(-4)` `therefore"Error"=(m.-m)/mxx100=0.5xx10^(-4)xx100=0.005%`.