In the movie Indiana Jones and the Raiders of the Lost Ark, Dr. Jones takes a golden idol for a pressure sensitive pad, replacing the golden idol (gold has a density of 19.32 g/cm3 )

Question

In the movie Indiana Jones and the Raiders of the Lost Ark, Dr. Jones takes a golden idol for a pressure sensitive pad, replacing the golden idol (gold has a density of 19.32 g/cm3 ) with a small leather bag of sand (did you watch the video in the W3 module?) The pressure pad descends and the Ph.D. hits the fan. Sand has an average density of 2.65 cm3 . Should Jones have been surprised?

Knowing that the idol (solid gold…what kind of tin can hack tribe worships a plated idol?) looks to have a volume of about 1 liter. What volume of sand should Jones have put on the pan to stop the alarm from going off?

Answer 1

Given that 1 Liter = 1000 cm³, the Mass of the gold idol = 19.32 g/cm³ *1000 cm³ = 19320 g

In order for Dr. Jones to avoid the boogie trap, he would have had to replace the relic with something of equal mass.

A small leather bag of sand would definitely not be a mass of 19320g so Dr. Jone should have not been surprised that things went south immediately!

The volume of sand he would have needed = 19320 g * [1 / (2.65 g/cm³) ] = 7290.57 cm³ = 7.3 Liters

Hope this helps!