The resistance of a conductor is given by:

where

is the resistivity of the material
L is the length of the conductor
A is its cross-sectional area
We can use this formula to solve both parts of the problem.
a) The length of the copper wire is L=1.0 m. Its diameter is d=0.50 mm, so its radius is

And its cross-sectional area is

The copper resistivity is

, therefore the resistance of this piece of wire is

b) The length of this piece of iron is L=10 cm=0.10 m. Its cross-sectional size is L=1.0 mm=0.001 m, so its cross-sectional area is

The iron resistivity is

, therefore the resistance of this piece of wire is
<em>Time = (the set distance) / (the object's traveling speed)</em>
Answer:
In order to make this force twice as strong, F' = 2 F, the distance would have to be changed to half i.e. r' = r/2.
Explanation :
The electric force between two point charges is directly proportional to the product of charges and inversely proportional to the square of the distance between charges. It is given by :

r is the separation between charges


If F'= 2F

In order to make this force twice as strong, F' = 2 F, the distance would have to be changed to half i.e.
. Hence, this is the required solution.
Answer:
Seismometer
Explanation:
Seismometer measures Earth quake epicenter while seismograph measures Earth quake size
Answer:
It helps the answer look clean. It also makes the work easier to work with.
Explanation:
Instead of writing a lot of zeros, all you have to do is add exponents to the number to show how much the decimal moved.