Question

A relative density bottle weighs 0.03kg when empty and 0.057kg when full of water. What will it weigh when full of kerosene of relative density 0.8?

Answer 1

Answer:

The mass of the kerosene is, $M_{k}$ =  0.021 kg  

Explanation:

Given data,

The mass of the empty density bottle, m₁ = 0.03 kg

The mass of density bottle filled with water, m₂ = 0.057 kg

The relative density of kerosene is, ρ = 0.8

                                        $\rho = \frac{density of kerosine}{density of water}$

                   Density of kerosene =  Density of water x relative density

                                                      = 1000 kg/m³ x 0.8

                                                      = 800 kg/m³

 The mass of water in the bottle,

                               $M_{w}$ = m₂ - m₁

                                                          = 0.057 kg -  0.03 kg

                                                          = 0.027 kg

The volume of bottle,

                                     $V =  \frac{M_{w}}{\rho}$

                                      $V =  \frac{0.027}{1000}$            

                                     V = 2.7 x 10⁻⁵ m³

The mass of the kerosene,

                                     $M_{k} = \rho_{k} \times V$

                                     $M_{k}$ = 800 x 2.7 x 10⁻⁵

                                                               = 0.021 kg

Hence, the mass of the kerosene is, $M_{k}$ =  0.021 kg