{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

# hmwk04 - Su(ycs73 HW04 Tsoi(58020 This print-out should...

This preview shows pages 1–3. Sign up to view the full content.

Su (ycs73) – HW04 – Tsoi – (58020) 1 This print-out should have 27 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. 001 (part 1 of 2) 10.0 points Two satellites A and B orbit the Earth in the same plane. Their masses are m and 6 m , respectively, and their radii r and 3 r , respectively. 3 r r 6 m B m A What is the ratio of the orbital speeds? 1. v B v A = 3 2. v B v A = 3 3. v B v A = 1 2 4. v B v A = 1 3 5. v B v A = 1 3 correct 6. v B v A = 1 9 7. v B v A = 2 8. v B v A = 1 2 9. v B v A = 2 10. v B v A = 9 Explanation: The force of gravity is responsible for hold- ing a satellite in its orbit, so the orbital cen- tripetal force is equal to the force of gravity: F r = m v 2 r = G M E m r 2 , where M E is the mass of the Earth, m is the mass of the satellite, and r is the radius of the orbit (from the Earth’s center). Thus the tangential speed v of an orbit at distance r is v = radicalbigg G M r radicalbigg 1 r . Since r A r B = 1 3 , the ratio v B v A = radicalbigg r A r B = 1 3 . 002 (part 2 of 2) 10.0 points Let 10 R E be the distance of the satellite A from the center of the Earth, where R E is the radius of the Earth. What is the gravitational acceleration due to the Earth at satellite A ? g is the gravita- tional acceleration at the surface of the Earth. 1. g A = g 11 2. g A = g 100 correct 3. g A = g 81 4. g A = g 11 5. g A = g 3 6. g A = g 10 7. g A = g 9 8. g A = g 121 9. g A = g 10 10. g A = g Explanation: g A = G M E r 2 A = G M E (10 R E ) 2 = 1 100 g .

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document