Question

Two spherical objects have masses of 8.1 multiply 10 power 2 kg and 4.5 multiply 10 power 8 kg. the gravitational attraction between them is 1.9multiply 10 power -3N.how far apart are their centre?
anyone else give the solution and answer is 110m.
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Answer 1

Answer: Given: Two spherical objects have masses of 8.1 x 10^2 kg and 4.5 x 10^8 kg. The gravitational attraction between them is 1.9 × 10^-3 N

To find: distance between their centres

Solution: If we want to find gravitational attraction between any two masses of a spherical figure, we can use newton's law universal gravitation having formula as

F = Gm1m2/r^2

here F is an attraction between masses, m1 and m2 are two masses, r is a separation between their centres

1.9 ×10^-3 = 6.67 ×10^-11 × 8.1×10^2 × 4.5× 10^8 / r^2

r^2 = 100 × 127.9

r = 113m

Therefore, the separation between the centres of the masses is 113m.