Mass of the Jupiter is 319 times more than that of the earth but it's acceleration due to gravity is only 2.5 times more than the earth.
Answers
It isn't. Jupiter's gravity is much greater, in direct proportion to its much greater mass (317.9 times Earth, if memory serves).
Jupiter's surface gravity is also higher, but only about 2.5 times as high as Earth's, because its greater mass is mostly offset by its much greater radius.
Perhaps you're thinking of Saturn? It also has much more mass and therefore gravity, however its surface gravity is slightly less than Earth's because, like Jupiter, it has a much greater radius than Earth.
A celestial body's surface gravity can be calculated in two ways:
Mass divided by radius (or diameter) squared Radius (or diameter) multiplied by density
As long as you're using multiples of Earth's mass, radius, diameter, and density as units, these are equivalent. Gas giants tend to have much lower density than rocky planets (around one-fifth), so smaller gas giants can easily have lower surface gravity than Earth, let alone a super-Earth.
because the radius of the jupiter is about 11 times greater then the earth, as gravity is directly proportional to the mass and inversely proportional to the square of the radius