solution-hw20

solution-hw20 - lai (yl8859) HW20 Ross (15200) 1 This...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: lai (yl8859) HW20 Ross (15200) 1 This print-out should have 7 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. 001 10.0 points A distant star has a single planet circling it in a circular orbit of radius 7 . 11 10 11 m. The period of the planets motion about the star is 703 days. What is the mass of the star? The value of the universal gravitational constant is 6 . 67259 10- 11 N m 2 / kg 2 . Correct answer: 5 . 76416 10 31 kg. Explanation: Let : G = 6 . 67259 10- 11 N m 2 / kg 2 , R B = 7 . 11 10 11 m , and T B = 703 day . T B = (703 day) parenleftbigg 24 h 1 day parenrightbigg 3600 s 1 h = 6 . 07392 10 7 s . According to Newtons explanation of Ke- plers third law R 3 B T 2 B = GM s 4 2 = const. The mass of the star is thus M s = 4 2 G R 3 B T 2 B = 4 2 6 . 67259 10- 11 N m 2 / kg 2 (7 . 11 10 11 m) 3 (6 . 07392 10 7 s) 2 = 5 . 76416 10 31 kg . 002 10.0 points An object is dropped from rest from a height 6 . 9 10 6 m above the surface of the earth. If there is no air resistance, what is its speed when it strikes the earth? The acceleration of gravity is 9 . 81 m / s 2 and the radius of the Earth is 6 . 37 10 6 m....
View Full Document

Page1 / 3

solution-hw20 - lai (yl8859) HW20 Ross (15200) 1 This...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online