Astro!010/1000-002- Homework #2 Due in class Monday, Sept. 25th page 1 o Name: S

Question

Astro!010/1000-002- Homework #2 Due in class Monday, Sept. 25th page 1 o Name: Student Number: Seek help from your TA, professor, or classmates if you need it, but all work must be your own. Show r 25th. Work in groups to solve the problems, but all writing here must be your own. If you won't be in class the date due, arrange to get it to your TA before the start of class. This homework is worth a total of 50 points. Late submissions will be given half credit until the solutions are posted (~1 week later). 1) Gravity (15 pts) Compare the gravitational force between Earth and the Sun in each of the following example to it's normal strength (i.e., what we have in our actual Solar System). Hint: compare with ratios! You should not need a calculator for these problems. (a) Earth orbits the sun at 5 AU. (b) Sun is replaced with a star with four times as much mass. (e) Earth orbits the Sun at 2 AU, but the Sun's mass is also doubled. (d) The Sun is replaced with a black hole with the same mass as the Sun.

Explanation / Answer

F = G m1 m2 / r 2   (a) 1Au is the distance between earth and Sun. If it is 5 AU , r2 becomes 5 x 5 = 25. The gravitational force becomes 25 times weaker than the normal strength. (b) If one of the mass is replaced with 4 times the mass, then force becomes 4 times stronger than the normal strength. (c). if distance is doubled, mass is doubled, formula becomes, F = G x 2 m1 m2 / 4r 2 . The force becomes half times weaker than the normal strength. (d). Black hole does not exert gravitational pull like Sun. Force will become zero.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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