This is due to the tilt of the earth on its axis. Although the Sun shines on Earth, because of how the Earth is tilted, the equator is more directly hit compared to places found on the poles. The poles are hit at an angle, therefore the sunlight they receive is lesser than the places at the equator.
Planet A;
m = the mass
Let r = the radius
Planet B:
Let M = the mass
The radius is 2r (twice the radius of planet A)
The surface gravitational acceleration of planets A and B (they have the same surface gravity) are

Answer: The mass of planet B is 4m.
When one object is rubbed against another, static electricity can be created. This is because the rubbing creates a negative charge that is carried by electrons.