Answer: a)1.27 *10^6 A/m^2; b) 57.9*10^6 Ω*m; c) 94.16*10^-6 m/s;
d) 4.29*10^-3 m^2/V*s
Explanation: In order to explain this problem we have to take into account the following expressions:
The current density is equal:
J=I/A where A is the area of the wire.
J=4A/(π*1*10^-6m^2)=1.27 *10^6 A/m^2
The resistence of the wire is given by:
R=L/(σ*A) where σ and L are the conductivity and the length of the wire, respectively.
Then we have:
σ= L/(R*A)=1/(5.5*10^-3*π*1*10^-6)=57.9 *10^6 Ω*m
The drift velocity of free electrons is given by:
Vd=i/(n*A*e) where n is the numer of electrons per volume. e is the electron charge.
then we have:
Vd=J/(n*e)= 1.27 *10^6/(8.43*10^28*1.6*10^-19)=94.16 *10^-6 m/s
Finally, the mobility of free electrons is equal to:
μ=Vd/E ; E=J/σ
μ=E*σ/J= 94.16*10^-6*57.9 *10^6/1.27 *10^6=4.29*10^-3 m^2/V*s
The answer is "Cold Front".
A cold front is characterized as the change zone where a cool air mass is supplanting a hotter air mass. Cold fronts for the most part move from northwest to southeast. The air behind a cold front is recognizably colder and drier than the air in front of it.
<span>A. three</span><span>
Oil spill can be very harmful to marine life because the chemical make up of oils can be poisonous to marine life. The oil can also affect the natural body temperature of marine animals especially to the small fish. Sea otters and sea birds are the most commonly affected by oil spills and those other marine animals that can be found in the shoreline. Heavy oils like the bunker oils used to fuel ships are the most harmful oil because when this oil stick to birds feathers, they may have an inability to warm themselves that could lead them to die.</span>
E=energy=5.09x10^5J = 509KJ
<span>M=mass=2250g=2.25Kg </span>
<span>C=specific heat capacity of water= 4.18KJ/Kg </span>
<span>ΔT= change in temp= ? </span>
<span>E=mcΔT </span>
<span>509=(2.25)x(4.18)xΔT </span>
<span>509=9.405ΔT </span>
<span>ΔT=509/9.405=54.1degrees </span>
<span>Initial temp = 100-54 = 46 degrees </span>
<span>Hope this helps :)</span>
Answer:
Acceleration, 
Explanation:
Initial speed of the skater, u = 8.4 m/s
Final speed of the skater, v = 6.5 m/s
It hits a 5.7 m wide patch of rough ice, s = 5.7 m
We need to find the acceleration on the rough ice. The third equation of motion gives the relationship between the speed and the distance covered. Mathematically, it is given by :
So, the acceleration on the rough ice 
and negative sign shows deceleration.
