Find the force of gravitational attraction between the earth (m = 6 x 1024 kg) and 80 kg man if he is standing at sea level. The distance of man from earth's center is 6.38 x 106 m.

Asked by sudiptaroy0607 | 8th Jan, 2022, 04:59: PM

Expert Answer:

From universal law of gravitation , Force F of attraction between earth and man is given as
 
begin mathsize 14px style F space equals space G cross times fraction numerator M space m over denominator R squared end fraction end style
where G = 6.674 × 10-11  N m2 kg-2 is universal gravitational constant , M = 6 × 1024 kg is mass of earth
 
and m = 80 kg is mass of man and R = 6.38 × 106 m .
 
F = [ 6.674 × 10-11 × 6 × 1024  × 80 ] / ( 6.38 × 106 )2  = 787 N
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If we consider g =  [  ( G M ) / R2 ] is the acceleration due to gravity , then gravitational force is calculated as
 
F = m × g = ( 80 × 9.8 ) N = 784 N

Answered by Thiyagarajan K | 8th Jan, 2022, 07:15: PM