A wire must be replaced in a circuit by a new wire of the same material but nine times longer. If the new wire's resistance is the same as the original wire's, what is the diameter of the new wire?

O the same as the original diameter
O one half the original diameter
O one third the original diameter
O three times the original diameter
O nine times the original diameter

three times the original diameter

Explanation:

From the wire's resistance formula, we can calculate the relation between the diameter of the wire and its length:

Here, d is the wire's diameter, is the electrical resistivity of the material and R is the resistance of the wire. We have

trig 15.3 cos

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.