Aresting adult requires about 240 ml of pure oxygen per minute and breathes about 12 times every minute. if inhaled air contains 20 percent oxygen by volume and exhaled air 16 percent, what is the volume of air per breath? (assume that the volume of inhaled air is equal to that of exhaled air.)

55.55 mL

Explanation:

Breathing is the process of inhaling air into and exhaling out of the lungs.

Total amount of oxygen required per minute = 240 mL

No. of breaths per minute = 12

Amount of oxygen required per minute

One breath = 1 inhalation + 1 exhalation

Lets assume, volume of air per breath = mL

Volume of oxygen in inhaled air = 20%

Volume of oxygen in inhaled air = 16%

Total volume of oxygen during one breath = (20%) + (16%)

This implies,

Thus, volume of air per breath = 55.55 mL

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.  

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.