Possible contaminate will be Proteus or Salmonella. To differentiate the two genera urease test can be accomplished. However, urease test, Proteus will produce a positive test result.
This test can be done to determine the ability of an organism to split urea. The principle of urease test is that urea is the product of decarboxylation of amino acid. Splitting of urea via hydrolysis will produce ammnonia and CO2. The CO2 produce allows the formation of bubbles.
C)1125 J because the formula for kinetic energy is 1/2 multiplied by mass multiplied by volume to the second power. So 1/2 multiplied by 10 multiplied by 15 to the second power is 1125 if that makes since.