Answer:
The ratio of the diameter of iron to Cu is;

Explanation:
R=(ρL)/A
- R is resistance,
- L is length,
- A is area,
- ρ is resistivity
- d is diameter
from the question the two materials have the same resistance per unit length.

for iron =
for copper
This means we can equate ρ/A for both materials.

re-arranging the equation we have,





Answer:
Yes it would be different on Earth and the moon
Answer:
This is the answer: The speed of a proton is about 5.0 × 10⁵ m/s
Explanation:
Because of the speeds of protons! :D