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.

Asked by Topperlearning User | 12th 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  | 12th Jul, 2016, 06:22: PM