Over time, the types of technology can vary and be improved upon so that more advanced techniques become more valued. This could be the situation with mining whereby back in the 1500's in underground mines the rock was broken by fire setting ie lighting a fire below the rock face to heat up the rock and then throwing cold water on it to crack it, so that it could be dug by hand. With the advent of explosives, this all changed so that the rock could be blasted. The increase in advance rates for an underground heading have thus gone from 5-20 feet per month to up to 300meters (984 ft) per month for a 24/7 mining operation, which is a huge improvement.
Answer:
Option c) are perpendicular to the electric field
Explanation:
Equipotential surfaces are perpendicular to the electric field. the electric field lines are projected outwards from the equipotential surface, i.e., the lines of the electric field are at 90
to the equipotential surface.
Equipotential surface are those surfaces that have the same potential at any point on the surface. Thus the potential difference at any point on the surface is zero due to same potential.
Any charge particle on this surface will move in a perpendicular direction to the Coulombian force. No work is done by the force on a particle moving on an equipotential surface.
Answer:
0.23 J
Explanation:
k*(36 - 28) = 23
so k = 23/8 N/cm
W = k(32 - 28)²/2 = 23/8 * 4²/2 = 23 N-cm = 0.23 J
Nitrogen is the most abundant of the gases present in the atmosphere. 78 percent of the atmospheric air comprises of nitrogen, oxygen makes up for 21 percent and all other gases make up for the remaining one percent. Oxygen is a highly flammable gas and in the absence of nitrogen it would not have been possible to utilize this atmospheric oxygen, hence the presence of nitrogen reduces its flammability and also neutralizes the toxicity of other gases.
