A uniform meter bar is supported at 30cm mark and block of 8N is placed at nearer end so that system remain in equilibrium. What will be weight of meter bar? a) 15N b) 12N c) 18N

An  atom  (ours, not carroll's) consists of a positively charged  nucleus, surrounded by one or more negatively charged particles called  electrons. the positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral. most of an atom's mass is in its nucleus; the mass of an electron is only 1/1836 the mass of the lightest nucleus, that of hydrogen. although the nucleus is heavy, it is quite small compared with the overall size of an atom. the radius of a typical atom is around 0.1 to 0.25 nanometres (nm), whereas the radius of a nucleus is about 10-6  nm.  *  if an atom were enlarged to the size of the earth, its nucleus would be only 200 feet in diameter and could easily rest inside a small football stadium.read more on -

Electoral current force mechanical advantage if the wheel and axle is 2 n and the output force is 20 n

Hi. i believe this is called a scientific  theory.cheers!

Electrical charge is measured in coulomb.(c). the amount of an electrical charge that moves in a circuit depends on the current flow and how long it flows for. a current of 10 a flows for 30 s,then 10 x=300 coulombs of electrical charge moves