Question

Surface gravity of different planets in correct decreasing order is

• A. Neptune, Jupiter, Saturn, Earth
• B. Jupiter, Neptune, Earth, Saturn
• C. Jupiter, Neptune, Saturn, Earth
• D. Jupiter, Uranus, Neptune, Saturn

Answer 1

Answer: (C)

Jupiter, Neptune, Saturn, Earth

Surface gravity of different planets has a unique surface gravity.
Newton's second law of motion: $F=ma$............(1)
Law of universal gravitation: $F_g=\frac{G{M}_1{M}_2}{R^2}$............(2)
The value of $G$ was originally determined experimentally by Henry Cavendish and has a value of $6.67\times {10}^{11}N{m}^3/kg{s}^2$
By using these two equations, one can derive another equation that shows the acceleration due to gravity at the surface of a planet, i.e., $g=\frac{GM}{R^2}$
Where $M$ is the mass of the planet and $R$ is its radius.
The surface gravity of the planets, as determined by the equation above and shown relative to Earth's gravity can be seen below:

Object: g/g-earth: Acceleration at the surface

Earth...............$1.0$...............$g=9.78m/s^2$ ($32.1ft/s^2$)

Jupiter.............$2.36$...........$g=23.1m/s^2$ ($75.9ft/s^2$)

Saturn.............$1.07$.............$g=9.05m/s^2$($29.4ft/s^2$)

Uranus............$0.889$...........$g=8.69m/s^2$($28.5ft/s^2$)

Neptune..........$1.12$.............$g=11.0m/s^2$($36.0ft/s^2$)

So, surface gravity of different planets in correct decreasing order isJupiter, Neptune, Saturn, Earth.