My Dad has a miniature Pyramid of Egypt. It is 5 inches in height. Dad was invited to display it at an exhibition. Dad felt it was too small and decided to build a scaled-up model of the Pyramid out of material whose density is (1 / 9) times the density of the material used for the miniature. He did a "back-of-the-envelope" calculation to check whether the model would be big enough.

If the mass (or weight) of the miniature and the scaled-up model are to be the same, how many inches in height will be the scaled-up Pyramid? Give your answer to two places of decimal.

• Mass of the square pyramid = a^2 *(h/3)* d; where a is the base length, h is height and d is the density of the material. If the new material has (1/9)th of the original density then height should be 9 times the original eight to keep the mass same. So, the answer is 5 * 9 = 45 inches.
• 10 years agoHelpfull: Yes(0) No(0)