Sun. ULTIPLE CHOICE·Choose the one alternative that best completes the statement

Question

Sun. ULTIPLE CHOICE·Choose the one alternative that best completes the statement or answers the question 2) List the four fundamental forces in nature. A) gravitational, electromagnetic, strong nuclear, weak nuclear B) gravitational, contact, strong nuclear, weak nuclear C) gravitational, normal, kinetic friction, static friction D) gravitational, electromagnetic, contact, nuclear E) gravitational, normal, tension, friction 3) What is the distance from the moon to the point between Earth and the Moon where the gravitational pulls of Earth and Moon are equal? The mass of Earth is 5.97x 1024 kg, the mass of the Moon is 7.35 x 1022kg, the distance between Earth and the Moon is 3.84x 108m, and 6 6.67 x10-11 Nm2/kg2. A) 3.83 x 106 m B) 3.45 x 108 m C) 3.83 x 107m D) 4.69 x 107m E) 4.69 x 106 m

Explanation / Answer

at distance r from moon the pulls of earth and moon are equal

consider a mass m is kept at r

Force exerted by moon on m, FM = G*Mmoon*m/r^2

Force exerted by earth on m, FE = G*Mearth*m/(d-r)^2

d = distance between earth and moon

FM = FE

Mmoon/r^2 = Mearth/(d-r)^2

7.35*10^22/r^2 = 5.97*10^24/((3.84*10^8)-r)^2

((3.84*10^8)-r)^2/r^2 = 5.97*10^24/(7.35*10^22) = 81.22

((3.84*10^8)-r)/r = sqrt81.22 = 9.01

3.84*10^8/r - 1 = 9.01

3.84*10^8/r = 10.01

r = 3.84*10^8/10.01

r = 3.83*10^7 m <<<-----------ANSWER

OPTION (C)

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.