Apiece of nichrome wire has a radius of 7.1 x 10-4 m. it is used in a laboratory to make a heater that dissipates 3.20×102 w of power when connected to a voltage source of 110 v. ignoring the effect of temperature on resistance, estimate the necessary length of wire.

the length of the Nichrome wire is 59.88 m

Explanation:

The resistance of a wire is determined by:

P = V² / R                              or    R = V² / P

where

We also know that

R = PL / A

where

Therefore, the length of the Nichrome wire is

L  = RA / ρ

L = (V²/P)(πr²) / ρ

L = V²πr² /  ρ P

L = (110 V)²(π)(7.1 × 10⁻⁴ m)² / (3.2 × 10² W)(100 × 10⁻⁸ Ω·m)

L = 59.88 m

answer; how far out of place which the object finished relative to the starting location;

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form