From the last problem, what is the ratio of the ppm change in co2 to the ppm change in ch4? assume that the concentrations of co2 and ch4 start at their present-day values of 400 ppm and 1.7 ppm, respectively.

An additional 10ppm of methane will change the upward IR heat flux (in tropical

atmosphere) from 289.29 W/m2

to 286.211 W/m2

, which is a reduction of 3.08

W/m2

.

An additional 10ppm of CO2 will change the upward IR heat flux from 289.29 W/m2

to 289.29 W/m2

, which is a change of 0.13 W/m2

.

Therefore, an additional 10 ppm of methane would have a much larger impact on

the outgoing infrared flux than an additional 10 ppm of CO2 at current

concentrations

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.