If the moon had twice the diameter with same mass and orbital distance from earth, then the high tides on Earth would be practically the same.
Explanation:
As the tides occurring in the earth is mostly due to the gravitational force of the moon acting on the earth. The distance between the earth and the moon mainly influences high tides. So, tidel force can be termed as directly proportionate to the gravitational forces acting between moon and earth.
As the gravitational forces act on Earth due to the moon will be directly proportionate to the product of masses of Earth and Moon and inversely proportionate to the distance squared (separation between Earth and Moon), due to the universal law of gravitation.
Thus, it can be stated that the diameter of the moon has no role to play in the high tides. As it is stated that the mass and distance almost remained the same, and there is only a change in the diameter of the moon, the high tides will not be exhibiting much change. Thus, on earth the high tides would be practically the same on increasing the diameter of the Moon.
