Answer:
8.333*10^-6 ohms
Explanation:
Resistivity of a material is expressed as;
p = RA/l
R is the resistance of the material
A is the cross sectional area
l is the length of the material
Given
R = 5 ohms
A = 0.5mm^2
A = 5 * 10^-7m^2
l = 30cm = 0.3m
Substitute into the formula;
p = (5 * 5 * 10^-7m^2)/0.3
p = 25 * 10^-7/0.3
p = 0.0000025/0.3
p = 8.333*10^-6
Hence its resistivity at 20 degrees Celsius is 8.333*10^-6 ohms
Answer:
36,67 degrees Celsius
Explanation:
The simplest way to approach this problem, given the information provided, is to simply start with the speed difference.
Goal: 353 m/s
Start: 343 m/s (at 20 degrees Celsius).
Difference: 10 m/s
Variation rate: 0.60 m/s/d (d = degree)

So, 16,67 degrees more than the starting point.
The temperature will then be 36.67 degrees Celsius, when the sound travels at the speed of 353 m/s.
That information describes the plane's speed.
If he had also told them what direction they were flying, then
they would have been able to put the two pieces of information
together, and they would know the plane's velocity.
2.5 better than the first one more game to go hard but I 46 the bucks