A research submarine can withstand an external pressure of 62 megapascals (million pascals) all the while maintaining a comfortable internal pressure of 101 kilopascals. How deep can it dive in the ocean before it would risk collapsing from the pressure

The depth will be equal to 6141.96 m

Explanation:

pressure on the submarine = 62 MPa = 62 x 10^6 Pa

we also know that = ρgh

where

ρ is the density of sea water = 1029 kg/m^3

g is acceleration due to gravity = 9.81 m/s^2

h is the depth below the water that this pressure acts

substituting values, we have

= 1029 x 9.81 x h = 10094.49h

The gauge pressure within the submarine = 101 kPa =  101000 Pa

this gauge pressure is balanced by the atmospheric pressure (proportional to 101325 Pa) that acts on the surface of the sea, so it cancels out.

Equating the pressure , we have

62 x 10^6 = 10094.49h

depth h = 6141.96 m

to treat tumors in the body

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.