38. The gravitational force between two electrons 1.00m apart is 5.42 x 10^ -71 N. Find the mass of an electron.

46. The moon is 3.9x10^5 km from Earth’s center and 1.5 x 10 ^8 km from the sun’s center. If the masses of the moon, Earth, and the sun are 7.3 x 10^22 kg, 6.0 x 10^24 kg, and 2.0 x 10^30 kg, respectively, find the ratio of the gravitational forces exerted by Earth and the sun on the moon.

Question

38. The gravitational force between two electrons 1.00m apart is 5.42 x 10^ -71 N. Find the mass of an electron.

46. The moon is 3.9x10^5 km from Earth’s center and 1.5 x 10 ^8 km from the sun’s center. If the masses of the moon, Earth, and the sun are 7.3 x 10^22 kg, 6.0 x 10^24 kg, and 2.0 x 10^30 kg, respectively, find the ratio of the gravitational forces exerted by Earth and the sun on the moon.

dan815 · Answer

G*m1*m2/r^2 = gravitional force

dan815 · Answer

G constant is 6.674×10^−11 N m2 kg−2

mayankdevnani · Answer

you have
$$F=G \frac{m1m2}{r^2} $$

mayankdevnani · Answer

out of these, r,F,G & m1=m2=m(the two being electron will have same mass)

mayankdevnani · Answer

now eqn becomes
$$F=G \frac{m^2}{r^2}$$

mayankdevnani · Answer

sunstitute values and then find m.

ok...   @Amberley    this is the answer of question no.1

mayankdevnani · Answer

answer of q.2 http://answers.yahoo.com/question/index?qid=20081109131438AAV4iR7