Answer:
Slightly above 20°c
Explanation:
The resistivity of silver is 1.59 x 10-8Ωm{ as discovered by experiment from scientist}
The resistivity of tungsten at 20°c is 5.6x10-8Ωm
We see the value is just an approximation of 4 times not exactly.
Answer:
B
Explanation:
The nucleus is made up of protons and neutrons, and electrons float around the neucleus in the electron cloud.
Answer:reactant,active site,enzyme below,substrate,products
Explanation:
Answer:
The part of the earth and its atmosphere in which living organisms exist or that is capable of supporting life.
Explanation:
It’s in the definition of biosphere. “Bio” means “life,” so “biosphere” is that portion of the Earth capable of supporting life.
Ok, assuming "mj" in the question is Megajoules MJ) you need a total amount of rotational kinetic energy in the fly wheel at the beginning of the trip that equals
(2.4e6 J/km)x(300 km)=7.2e8 J
The expression for rotational kinetic energy is
E = (1/2)Iω²
where I is the moment of inertia of the fly wheel and ω is the angular velocity.
So this comes down to finding the value of I that gives the required energy. We know the mass is 101kg. The formula for a solid cylinder's moment of inertia is
I = (1/2)mR²
We want (1/2)Iω² = 7.2e8 J and we know ω is limited to 470 revs/sec. However, ω must be in radians per second so multiply it by 2π to get
ω = 2953.1 rad/s
Now let's use this to solve the energy equation, E = (1/2)Iω², for I:
I = 2(7.2e8 J)/(2953.1 rad/s)² = 165.12 kg·m²
Now find the radius R,
165.12 kg·m² = (1/2)(101)R²,
√(2·165/101) = 1.807m
R = 1.807m
