Answer:
Scalar quantity can never be Negative. Because scalar has only magnitude not direction. And magnitude can't be negative.
Explanation:
Answer:
Explanation:
The power provided by a resistor (wire in this case) is given by:
.
The resistance of a wire is given by:
Where for the resistivity the one of the copper should be used: 
.
The area A is that of a circle, which written in terms of its diameter is:
Putting all together:
Which for our values is:
Force, pressure, and charge are all what are called <em>derived units</em>. They come from algebraic combinations of <em>base units</em>, measures of things like length, time, temperature, mass, and current. <em>Speed, </em>for instance, is a derived unit, since it's a combination of length and time in the form [speed] = [length] / [time] (miles per hour, meters per second, etc.)
Force is defined with Newton's equation F = ma, where m is an object's mass and a is its acceleration. It's unit is kg·m/s², which scientists have called a <em>Newton</em>. (Example: They used <em>9 Newtons</em> of force)
Pressure is force applied over an area, defined by the equation P = F/A. We can derive its from Newtons to get a unit of N/m², a unit scientists call the <em>Pascal</em>. (Example: Applying <em>100 Pascals </em>of pressure)
Finally, charge is given by the equation Q = It, where I is the current flowing through an object and t is how long that current flows through. It has a unit of A·s (ampere-seconds), but scientist call this unit a Coulomb. (Example: 20 <em>Coulombs</em> of charge)
Read each statement, one at a time, and form the picture in your mind.
<em>Statement #1</em> should make you feel all warm and fuzzy inside.
Statements #2, #3, and #4 should make your red flag wave on the inside, and should make you giggle on the outside when you realize how absurd each of those is.
Answer:
We use electrolysis to prevent a material from rusting,
The metal forms a coating around the material and hence prevents any contact between the material and the environment
This process also gives us the physical strength of the material and the aesthetic properties of the coated metal
the metal commonly used to coat the object is Zinc and the process is called galvanisation
