Answer:
Therefore the ratio of diameter of the copper to that of the tungsten is

Explanation:
Resistance: Resistance is defined to the ratio of voltage to the electricity.
The resistance of a wire is
- directly proportional to its length i.e

- inversely proportional to its cross section area i.e

Therefore

ρ is the resistivity.
The unit of resistance is ohm (Ω).
The resistivity of copper(ρ₁) is 1.68×10⁻⁸ ohm-m
The resistivity of tungsten(ρ₂) is 5.6×10⁻⁸ ohm-m
For copper:


......(1)
Again for tungsten:

........(2)
Given that
and 
Dividing the equation (1) and (2)

[since
and
]



Therefore the ratio of diameter of the copper to that of the tungsten is

450 J / 3 s = 150 J/s = 150 watts.
Same magnitude (1000N) and opposite direction
you may also answer -1000 N
Answer:
b) 4781 N
Explanation:
Because there is a redius do this question is talking about the acceleration force which= mv^2/r
so a=15^2/80=2.8125 m^2/s
so the force will be = m.a
F =1700×2.8125=4781.25 N
The statement is false because as the temperature of water is decreased from 4C to 0C, <em>expansion</em> occurs.
You should understand that this is very weird behavior for any compound ... within a small temperature range, the stuff actually gets bigger as it gets colder. That's why cubes float in your sody, and bergs float in the ocean.
Water is one of only two known substances that do this. And if water didn't do it, then life on Earth would not be possible.
Hmmm....