question_answer

  Shashank placed an iron cuboid of dimensions 4 cm x 7 cm x 10 cm on a tray  containing fine sand. He placed the cuboid in such a way that it was made to lie on the sand with its faces of dimensions (i) 4 cmx 7 cm,                   (ii) 7 cm x 10 cm, (iii) 4 cmx 10 cm. If the density of iron is nearly 8 g/cm3 and . g=10m/s2, find the minimum and maximum pressure as calculated by  Shashank.                        

Answer:

                Mass of cuboid = Volume x Density = (4 cmx 7 cmx 10 cm) x 8 g /cm3 ( Volume of cuboid ) = 2240 g= 2.24 kg Force applied by the cuboid on the sand = mg                           Pressure will be minimum when area of the face of cuboid kept on sand is maximum i.e., in the case of face with 7 cm x 10 cm. Area of the face = 7 cm x 10 cm     Minimum pressure Pressure will be maximum when area of face of cuboid kept on the sand is minimum i.e., in the case of face with 4 cm x 7cm. Area of the face = 4 cm x 7 cm                Maximum pressure