<span>mechanical energy is E=mgh+ 1/2 mV²=2*9.8*1+1/2*2*4.4²=38.96J,
the only force is P, that is a conservative force so the answer is
</span>mechanical energy is conserved and its value is <span>38.96J, </span>
Answer with Explanation:
We are given that
Length of wire 1=
Length of wire 2=
Resistivity of copper wire=
Resistivity of aluminum wire=
Wire 1=Copper wire
Wire 2=Aluminum wire
Diameter of both wires are same and resistance of both wires are also same.
We know that
Resistance =
When diameter of wires are same then their cross section area are also same .

When resistance and area are same then the length of wire depend upon the resistivity of wire .
The length of wire is inversely proportional to resistivity.
When resistivity is greater then the length of wire will be short and when the resistivity is small then the length of wire will be large.

Therefore, 
Hence, the length of wire 1 (copper wire) is greater than the length of wire 2 (aluminum).


I think one of them is composed primarily of plant material,
and the other is composed primarily of dead dinosaurs.
42) The sailboat travels east with velocity

, while the current moves south with speed

. Since the two velocities are perpendicular to each other, he resultant velocity will be given by the Pytagorean theorem:

and the direction is in between the two original directions, therefore south-east. So, the correct answer is
D) 42 mph southeast
43) Since the light moves by uniform motion, we can calculate the distance corresponding to one light year by using the basic relationship between velocity, space and time. In fact, we know the velocity:

and the time is one year, corresponding to:

therefore, the distance corresponding to one light year is:

Therefore, the correct answer is D.
44) For the purpose of the problem, we can assume that the light travels instantaneously from the flash to us (because the distances involved are very small), so the time between the flash and the thunder corresponds to the time it took for the sound to travel to us.
The speed of sound is

And since the time between the flash and the thunder is t=3 s, the distance is

Therefore, the correct answer is A) 3/5 mile.