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:
Its a social media platform
Explanation:
When we jump from the truck and accelerate towards the earth surface, the earth also accelerates towards us but it's acceleration is very negligible.
To find the answer, we need to know about the acceleration of earth due to the gravitational attraction.
<h3>What's the gravitational force between the earth and a person?</h3>
- Gravitational attraction force is GMm/r² between the earth and a person.
- M= mass of the earth
m= mass of the person
r= separation between them.
<h3>What's the acceleration of the earth towards the person when he jumps from a truck?</h3>
- According to Newton's second law, Force = M×acceleration
- Acceleration= Force / M
- Here, Force = GMm/r²,
so acceleration of earth= Gm/r²
- As this acceleration is very small, so we can't notice it.
Thus, we can conclude that the earth also accelerates towards us.
Learn more about the gravitational force here:
brainly.com/question/72250
#SPJ4
Energy is not created and not destroyed it will only change form
So heres your answer ; It is given off as other forms of energy/light and heat !!
=answer 2nd one
Answer: true
Explanation: this is were it is located