AC for household is 230V

Speed is the rate of change of displacement with respect to its surrounding. Since the speed of a body is irrespective of its direction, therefore it is a scalar quantity.

Natural uranium as found in the Earth's crust is a mixture largely of two isotopes:uranium-238 (U-238), accounting for 99.3% and uranium-235 (U-235) about 0.7%. The isotope U-235 is important because under certain conditions it can readily be split, yielding a lot of energy.

always derives gravitational energy