The main requirement for a good conductor of electricity is to have a lot of valence electrons. Valence electrons are the electrons of the outer shells of atoms not bound with other atoms (for example through covalent bounds). These electrons are "free to escape" as soon as an electric field with enough intensity is applied to the material, and therefore these electrons will be free to move in the material producing an electric current.
<u>C</u> is the correct answer, because energy cannot be created neither destroy. The energy is changing from chemical to from electric to light, and from light to heat.
Answer:
A. It is always a positive force
Explanation:
Hooke's law describes the relation between an applied force and extension ability of an elastic material. The law states that provided the elastic limit, e, of a material is not exceeded, the force, F, applied is proportional to the extension, x, provided temperature is constant.
i.e F = - kx
where k is the constant of proportionality, and the minus sign implies that the force is a restoring force.
The applied force can either be compressing or stretching force.
let the distance of pillar is "r" from one end of the slab
So here net torque must be balance with respect to pillar to be in balanced state
So here we will have
here we know that
mg = 19600 N
Mg = 400,000 N
L = 20 m
from above equation we have
so pillar is at distance 10.098 m from one end of the slab