Answer:
The decrease is due to the bulge at the equator (putting more distance between the rest of the planet and the surface
Explanation:
 
        
             
        
        
        
There is approximately 2.54 cm that equals to 1 inch. So your closet answer would be the first choice. :)
        
                    
             
        
        
        
1) 72/4 = 18 years
2) 72/10 = 7.2 years
3) 72/13 = 5.54 years
Explanation: With the rule of 72, you simply take 72 and divide it by whatever the rate of return (or return on investment) is.
Let me know if you have any questions.
 
        
             
        
        
        
I assume you're talking about a pilot. If the ejection seat has an acceleration of 8<em>g</em>, then it would exert a normal force of 8<em>g</em> (70 kg) ≈ 5600 N.
(This is assuming the pilot is flying horizontally at a constant speed, and the seat is ejected vertically upward.)
To reiterate, this is *only* the force exerted by the seat on the pilot. Contrast this with the <em>net</em> force on the pilot, which would be the normal force minus the pilot's weight, 5600 N - (70 kg)<em>g</em> ≈ 4900 N.
If instead the seat ejects the pilot directly downward, the force exerted by the seat would have the same magnitude of 5600 N, but its direction would be reversed to point downward, making it negative. But the <em>net</em> force would change to -5600 N - (70 kg)<em>g</em> ≈ -6300 N