Answer:

Explanation:
The electric flux is defined as the multiple of electric field and the area that the electric field passes through, such that

When calculating the electric flux, the angle between the directions of electric field and the area becomes important, especially if the angle is changing with time.
The above formula can be rewritten as follows

where θ is the angle between the electric field and the area of the loop. Note that, the direction of the area of the loop is perpendicular to the plane of the loop.
If the loop is rotating with constant angular velocity ω, then the angle can be written as follows

At t = 0, cos(0) = 1 and the electric flux through the loop is at its maximum value.
Therefore the electric flux can be written as a function of time

It’s doesn’t change meaning it’s 0
This is a statement not a question .
Answer:
acceleration = 45 m/s²
Time = 20 seconds
Explanation:
We are given;
Distance; s = 90m
Final velocity;v = 90 m/s
Since shot from rest, initial velocity;u = 0 m/s
So, to find the acceleration, we can use Newton's 2nd law of motion which is;
v² = u² + 2as
Where a is acceleration
Plugging in the values;
90² = 0² + 2a(90)
8100 = 180a
a = 8100/180
a = 45 m/s²
Now, for the time, we will use Newton's 1st law of motion which is;
v = u + at
Where t is time;
So;
90 = 0 + 4.5t
90 = 4.5t
t = 90/4.5
t = 20 seconds