I can't particularly place what Icelandic contributed.
But every other culture contributed majorly.
So I would go for option b.
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
Answers all in picture below
:
Complete Question
A football coach walks 18 meters westward, then 12 meters
eastward, then 28 meters westward, and finally 14 meters
eastward.
a
From this motion what is the distance covered
b
What is the magnitude and direction of the displacement
Answer:
a

b
Magnitude
Direction
West
Explanation:
From the question we are told that
The first distance covered westward is ![d_w_1 = 18 \ m /tex] The first distance covered eastward is [tex]d_e1 = 12 \ m /tex] The second distance covered westward is [tex]d_w_2 = 28 \ m /tex] The second distance covered eastward is [tex]d_e2 = 14 \ m /tex] Generally the distance covered is mathematically represented as [tex]D = d_w1 + d_w2 + d_e1 + d_e2](https://tex.z-dn.net/?f=d_w_1%20%20%3D%20%2018%20%5C%20%20m%20%2Ftex%5D%3C%2Fp%3E%3Cp%3E%20%20%20%20%20The%20%20first%20distance%20covered%20eastward%20is%20%5Btex%5Dd_e1%20%3D%20%2012%20%5C%20%20m%20%2Ftex%5D%3C%2Fp%3E%3Cp%3E%20%20%20%20%20%20The%20second%20distance%20covered%20westward%20is%20%5Btex%5Dd_w_2%20%20%3D%20%2028%20%5C%20%20m%20%2Ftex%5D%3C%2Fp%3E%3Cp%3E%20%20%20%20%20%20The%20%20second%20distance%20covered%20eastward%20is%20%5Btex%5Dd_e2%20%3D%20%2014%20%5C%20%20m%20%2Ftex%5D%3C%2Fp%3E%3Cp%3E%20%20%20%3C%2Fp%3E%3Cp%3EGenerally%20the%20distance%20covered%20is%20mathematically%20represented%20as%20%3C%2Fp%3E%3Cp%3E%20%20%20%20%20%20%5Btex%5DD%20%3D%20%20d_w1%20%2B%20d_w2%20%2B%20d_e1%20%2B%20d_e2)
=> 
=> 
For the second question eastward is in the direction of the positive x-axis so it would be positive and westward is in the direction of the negative x-axis so it would be negative
The magnitude of the displacement is

=>
=>
The direction is west
Answer:
Displacement: 2.230 km Average velocity: 1.274
Explanation:
Let's represent displacement by the letter S and the displacement in direction 49.7° as A. Displaement is a vector, so we need to decompose all the bird's displacement into their X-Y compoments. Let's go one by one:
- 0.916 km due east is an horizontal direction and cane be seen as direction towards the negative side of X-axis.
- 0.928 km due south is a vertical direction and can be seen as a direction towards the negative side of Y-axis.
- 3.52 km in a direction of 49.7° has components on X and Y axes. It is necessary to break it down using trigonometry,
First of all. We need to sum all the X components and all the Y componets.
∑
⇒ ∑![Sx = [tex]3.52cos(49.7) - 0.916](https://tex.z-dn.net/?f=Sx%20%3D%20%5Btex%5D3.52cos%2849.7%29%20-%200.916)
∑
∑
⇒ ∑
∑
The total displacement is calculated using Pythagoeran therorem:
⇒

With displacement calculated, we can find the average speed as follows:
⇒ 
