Question

3. The average radius of earth is 6400 km. Calculate the mass of earth. (acceleration due to gravity on earth is 9.8 m/sec^). (hint: use the relation between 'g' and 'G', where the terms have their usual meanings).​

Answer 1

Explanation:

g= R/2

GM

Given, G=6.67×10

−11

Nm

2

kg

−2

R=6.4×10

6

m

g=9.8ms

−2

∴M=

G

gR

2

=

6.67×10

−11

9.8×6.4×6.4×10

12

≈6×10

24

kg