A box of mass 10 kg and dimensions 2m x 2m x 2m is kept on floor. Each of its side is reduced by half metre and its mass reduces to 6kg. Find the ratio of the pressure exerted on the floor before and after the reduction.

CBSE Class 9 Answered

Asked by Topperlearning User | 12 Jul, 2016, 04:22: PM

Expert Answer

$begin mathsize 12px style Area space equals space 2 straight m space straight x space 2 straight m space equals space 4 space straight m squared space space space Mass space before space reduction comma space straight m subscript 1 space equals space 10 space kg space space space Weight space before space reduction comma space straight w subscript 1 space equals space mg space equals space 10 space straight x space 9.8 space equals space 98 space straight N space space space Pressure space before space reduction space equals space straight P subscript 1 straight P subscript 1 space end subscript equals space 98 over 4 straight P subscript 1 space equals space 24.5 space Pa After space reduction comma space space space Area space equals space 1 straight m space straight x space 1 straight m space equals space 1 straight m squared space space space Mass comma space straight m subscript 2 space equals space 6 space kg space space space Weight comma space straight w subscript 2 space equals space 6 space straight x space 9.8 space equals space 58.8 space straight N space space space Pressure space after space reduction space equals space straight P subscript 2 straight P subscript 2 space equals space fraction numerator 58.8 over denominator 1 end fraction straight P subscript 2 space equals space 58.8 space Pa Hence comma space ratio space is colon straight P subscript 1 over straight P subscript 2 space equals space fraction numerator 24.5 over denominator 58.8 end fraction end style$

Answered by | 12 Jul, 2016, 06:22: PM