Question

Crocodiles/plesiosaurs swallowed stones (swallowed stones are called gastroliths) arguably for buoyancy

versus feeding (see Stomach Stones for Feeding or Buoyancy? The Occurrence and Function of

Gastroliths in Marine Tetrapods, Michael A. Taylor, Philosophical Transactions: Biological Sciences, Vol.

341, No. 1296 (Jul. 29, 1993), pp. 163-175 ).

Consider a physics salt water crocodile (the picture on the right) of mass 1225kg: the surface area of its head is

~ 0.65m by 0.35m. If it swallows 1 percent of its body weight in stones, by how much does it sink?

https://becrocwise.nt.gov.au/about-crocodiles/did-you-know

Hint: Your solution must include: a FBD! Maybe two FBDs: one before swallowing and one after. Volume

change will be the surface area of the head multiplied by the amount sunk. Draw big clear well-labelled

pictures! Show that h= Δ m/Aρ f . No marks without Newton

Answer 1