Explanation:
The dimension of the book is 1.75 m × 2.25 m. If the book ends up at its initial position. The displacement of the book is equal to zero as the object reaches to its initial position.
If it completes its motion in 23 s, t = 23 s
Total displacement of the book is equal to its perimeter. It is given by :

The net displacement divided by total time taken is called the average velocity of an object. Here, the displacement is 0. So, average velocity is 0.
The average speed of an object is given by :


v = 0.347 m/s
So, the average speed of the book is 0.347 m/s. Hence, this is the required solution.
Slightly downstream for the shortest possible time
Answer: The frequency heard is 562.7 Hz.
Explanation: <u>Doppler</u> <u>Effect</u> happens when there is shift in frequency during a realtive motion between a source and the observer of that source.
It can be calculated as:

where:
c is the speed of light (c = 332m/s)
all the subscripted s is related to the Source (frequency, velocity);
all the subscripted o is related to the Observer (frequency, velocity);
As the source is moving towards the observer and the observer is moving towards the source, the velocities of each are opposite related to direction.
So, the frequency perceived by the observer:



= 562.7 Hz
At this condition, the observer hears the train's horn in a perceived frequency of 562.7 Hz
Answer:
Q = ba⁴ * ε₀
Explanation:
From Gauss's Law, we know that
flux Φ = Q / ε₀
where ε₀ = 8.85e-12 C²/N·m²
and also,
Φ = EAcosθ
The field is directed along the x-axis, so that all of the flux passes through the side of the cube at x = a. This means that θ = 0º, and thus
Φ = EAcos0
Φ = EA
E = bx² meanwhile, we are interested in the point where x = a, so we substitute and then
E = ba²
Since A = a² for the cube face, we have
Q / ε₀ = E * A
Q / ε₀ = ba² * a²
so that
Q = ba⁴ * ε₀
Answer:
b
Explanation:
he keep the thermoter in the water longer