The coefficient of volume expansion of a material is 5 10⁻⁴ o ⁻¹ . The fractional change in its density for a 40^ C rise in temperature is nearly.

Step-by-step solution

As density, 1 V Where, V= volume We have, ₂ ₁ = V₁ V₂ = V₁ V₁(1+r ) aligned & r= coefficient of cubical expansion & = rise of temperature & Since, ₂= ₁(1-r ) & Here, r=5 10⁻⁴ ^ C ⁻¹ aligned =40^ C So, in given case ₂ ₁ =1-5 10⁻⁴ 40=1-2 10⁻²=0.08 Hence, fractional change in density = ₁ ₁ = ₂- ₁ ₁ = ₂ ₁ -1 Fractional change is ₁ =0.08-1=-0.02 Here, negative sign shows decrease in density.