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
Answer:
The unit of charge is the Coulomb (C), and the unit of electric potential is the Volt (V), which is equal to a Joule per Coulomb (J/C).
Explanation:
Magnetic field describea magnet's ability to act at a distance
The time taken for the light to travel from the camera to someone standing 7 m away is 2.33×10¯⁸ s
Speed is simply defined as the distance travelled per unit time. Mathematically, it is expressed as:
<h3>Speed = distance / time </h3>
With the above formula, we can obtain the time taken for the light to travel from the camera to someone standing 7 m away. This can be obtained as follow:
Distance = 7 m
Speed of light = 3×10⁸ m/s
<h3>Time =?</h3>
Time = Distance / speed
Time = 7 / 3×10⁸
<h3>Time = 2.33×10¯⁸ s</h3>
Therefore, the time taken for the light to travel from the camera to someone standing 7 m away is 2.33×10¯⁸ s
Learn more: brainly.com/question/14988345
Answer:
a) 
b) 
Explanation:
The frequency of the 
harmonic of a vibrating string of length <em>L, </em>linear density 
under a tension <em>T</em> is given by the formula:
a) So for the <em>fundamental mode</em> (n=1) we have, substituting our values:
b) The <em>frequency difference</em> between successive modes is the fundamental frequency, since:
