010: A new planet (tentatively named “Melmac") is found in a circular orbit with a period of 571 years. The sun has a mass of 1.9891x1030 kg. How far away is the planet in Astronomical Units (AU) ? Note: An A.U. is 1.496x1011 m.

An intergalactic spaceship arrives at a distant planet that rotates on its axis with a period of T = 31 hours. The mass of the planet is M = 2.1 • 1025 kg. The spaceship enters a circular orbit with an orbital period that is equal to the planet's period for the rotation about its axis, T.   a.  Enter an expression for the radius of the spaceship’s orbit.  b.  Calculate the orbital radius in meters.

Two planets orbit a star. You can ignore the gravitational interactions between the planets. Planet 1 has orbital radius r₁, and planet 2 has r₂ = 4r₁ Planet 1 orbits with period T₁ Planet 2 orbits with period A. T₂ = -1/T₁ B. T₂=2T₁ C. T₂ = 4T₁ D. T₂=8T₁

2. a. Consider two planets orbiting a distant star. Planet A is further from the star. A is orbiting at a speed of 14625 m/s and has an orbital period of 12.45 years. What is the radius of A's orbit? Hint: remember to convert the period into seconds. 4.57E11 Previous submissions: 457000000000 b. What is the mass of the star? 1.465E30 Previous submissions: 1.465e30 kg c. Planet B is closer in. B has a larger velocity of 38500 m/s. What is the radius of B's orbit? 6.598E10 Previous submissions: m 65980000000 m m kg m incorrect incorrect V incorrect

The moon on Mars Phobos ( Fear) and Deimos ( Terror) are very close to the planet compared to Earth's Moon. Their orbital radii are 9,376 km and 23,463.2 km respectively. A) what is the orbital speed of Phobos to that of Deimos? B) If the period of Phobos orbits 7hr 39.2 min, what is the mass of Mars? C) Calculate the orbital period of Deimos.

Scientists have discovered a distant planet with a mass of 8.2x1023 kg. The planet has a small moon that orbits with a period of 6 hours and 36 minutes. Use only this information (and the value of G) to calculate the radius of the moon's orbit (in units of 106 m).

Planet X with a radius of 4.0 Rearth⊕ is found orbiting a star of mass 0.80M⊙ . The eccentricity of its orbit is 0.05, and at its farthest approach to the star, it is 0.63 AU away, while at its closest approach to the star, it is 0.57 AU away.  a. How long does it take Planet X to make a complete orbit around its star in years? b.The semi major axis of the planet is changed such that its closest approach to the star is now 2.9 AU. Would the gravitational force exerted by the star on Planet X increase or decrease? By what factor? Would the gravitational force exerted by Planet X on the star increase or decrease? By what factor?  c. The mass of the star was increased to 2.4M⊙ . Would the gravitational force exerted by it on Planet X increase or decrease? By what factor? Would the gravitational force exerted by Planet X on the star increase or decrease? By what factor?   d. What must the mass of Planet X be in Mearth⊕ such that an astronaut on its surface would have the same weight as…

2. The planet Jupiter has an orbital period of 4332.8 days, and its greatest distance (aphelion distance) from the Sun is 5.455 AU {where 1 AU = 1 Astronomical Unit = 1.496x10'' m}. The mass of the planet Jupiter is 1.898x1027 kg and the mass of the Sun is 1.988x1030 kg. {G = 6.67x10'" Nm/kg?) (a) Calculate the perihelion distance (closest distance) in Astronomical Units (AU) of the planet Jupiter from the Sun. (b) Calculate the eccentricity of planet Jupiter's orbit around the Sun. (c) Calculate the smallest speed of planet Jupiter around the Sun in km/s. At what point in Jupiter's orbit does Jupiter have its smallest speed?

mass of 5.98 x 1024 kg. The radius of Earth 11. Sally has a mass of 50.0 kg and Earth has a mass of 5.98 × 10 kg. The radius of Earth is 6.371 x 10 m. a. What is the force of gravitational attraction between Sally and Earth? b. What is Sally's weight?

4. Astronomers use a telescope to watch a small moon orbit a planet in our solar system. They find that it takes the moon 14 days to go around the planet once, and they estimate the radius of the moon's orbit is about 4.2 x 10² meters. a. From this information, estimate the mass of the planet. b. Using the mass you found in part (a), estimate the free-fall acceleration on the planet's surface if it has a radius of 3.8 x 106 meters.