To solve this problem we will apply the concepts related to volume, as a function of length and area, as of mass and density. Later we will take the same concept of resistance and resistivity, equal to the length per unit area. Once obtained from the known constants it will be possible to obtain the area by matching the two equations:
Mass of copper wire
Density
Resistively of copper 
Resistance (R) = 0.390\Omega
Volume is defined as,

(1)
We know that,


(2)
Multiplying equation we have




Therefore the length of the wire is 1.68m
Answer:
1. To determine the average speed for the first day of the trip, the total distance traveled would have to be acquired and then how long it took to arrive at the final destination, only including the time that was actually traveled and not any time that was accumulated by any rest stops. Once you have this information, you have to divide the distance over time and you have the average speed (mph).
2. To determine the instantaneous speed, you would just have to look at the speedometer, which tells you at what speed the car is traveling at that exact moment.
Explanation:
I took physics 121 and got the same question. This is my answer that i used and my teacher said it was right.
Solar system energy. electoral power engery motion force engery . wind energy. kinetic energy
here we know that the speed of the signal is same as the speed of light
so here we will have

the altitude of the airplane is given as

now we know that time taken by the signal to reach the control tower is given as

now it is given as


so above is the time taken by the signal to reach the control tower
F=ma
Velocity is Distance over time so Vf = 75/15 = 5m/s
Find acceleration V=Vo+at. plugging in the values you know, you get
0.33m/s^2
F=(2100)(0.33)=693N