The cooling on earth's surface (extrusive) makes a molten rock to become glassy. The lava cools so fast that crystals don't have time to form, which makes it glassy. Hope this helps!
Yes because if not people wouldn't understand how did you calculate electric field strength.
Answer:
Explanation:
height of Ellipse
i.e.
Width of Ellipse 
i.e.
Equation of a vertical Ellipse is
at
Answer:
True.
Explanation:
If the sum of the external forces on an object is zero, then the sum of the external torques on it must also be zero.
The net external force and the net external torque acting on the object have to be zero for an object to be in mechanical equilibrium.
Hence, the given statement is true.