The semi-major axes of the orbits of mercury and mars are respectively 0.387 and 1.524 in astronomical unit. If the period of Mercury is 0.241 year, what is the period of Mars.

Talking the mass and radius of the earth as the units of mass and distance respectively, the mass of Mars turns out to be 0.107 unit and radius 0.53 units. What is the acceleration due to gravity on the Mar's surface? What will be the weight of a person on Mars if he weighs 98kg on earth.

A comet (assumed to be in an elliptical orbit around the sun) is at a distance of 0.4 AU from the sun at the perihelion. If the time period of the comet is 125 years, what is the aphelion distance ? AU : Astronomical Unit.

The radius of the nearly circular orbit of mercury is 5.8xx10^(10) m and its orbital period is 88 days. If a hypothetical planet has an orbital period of 55 days, what is the radius of its circular orbit ?

The radius of the nearly circular orbit of mercury is 5.8xx10^(10) m and its orbital period is 88 days. If a hypothetical planet has an orbital period of 55 days, what is the radius of its circular orbit ?

The mean diameters of Mars and Earth are 6.9 xx 10^3 km and 1.3 xx 10^4 km, respectively. The mass of Mars is 0.11 times Earth's mass. (a) What is the ratio of the mean density (mass per unit volume) of Mars to that of Earth? (b) What is the value of the gravitational acceleration on Mars? (c) What is the escape speed on Mars?

A planet revolves round the sun in an elliptical orbit of minor and major axes x and y respectively . Then the time period of revolution is proportional to