Discover the Orbital Period of a Planet Using Newton's Law of Gravitation

  • Thread starter Thread starter lnl
  • Start date Start date
AI Thread Summary
Using Newton's version of Kepler's third law, the orbital period of a planet can be determined by the formula T^2 = (4π^2/GM) * r^3, where T is the orbital period, G is the gravitational constant, M is the mass of the star, and r is the distance from the star. In this scenario, with a planet twice the mass of Earth orbiting at 1 AU from a star of the same mass as the Sun, the mass of the planet does not affect the orbital period. The orbital period remains the same as Earth's, which is one year. Participants are encouraged to share their calculations or any difficulties they encounter for further assistance. Understanding these principles is essential for exploring celestial mechanics.
lnl
Messages
1
Reaction score
0
Question:

Use Newton's version of Kepler's third law to answer the following questions. (Hint: The calculations for this problem are so simple that you will not need a calculator.) Imagine another solar system, with a star of the same mass as the Sun. Suppose there is a planet in that solar system with a mass twice that of Earth orbiting at a distance of 1 AU from the star. What is the orbital period of this planet? Explain.

Any thoughts?
 
Physics news on Phys.org
Welcome to PF!

lnl said:
Use Newton's version of Kepler's third law to answer the following questions. (Hint: The calculations for this problem are so simple that you will not need a calculator.) Imagine another solar system, with a star of the same mass as the Sun. Suppose there is a planet in that solar system with a mass twice that of Earth orbiting at a distance of 1 AU from the star. What is the orbital period of this planet? Explain.

Hi lnl! Welcome to PF! :smile:

Show us what you've tried, and where you're stuck, and then we'll know how to help. :smile:
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top