Answer:
E/4
Explanation:
The formula for electric field of a very large (essentially infinitely large) plane of charge is given by:
E = σ/(2ε₀)
Where;
E is the electric field
σ is the surface charge density
ε₀ is the electric constant.
Formula to calculate σ is;
σ = Q/A
Where;
Q is the total charge of the sheet
A is the sheet's area.
We are told the elastic sheet is a square with a side length as d, thus ;
A = d²
So;
σ = Q/d²
Putting Q/d² for σ in the electric field equation to obtain;
E = Q/(2ε₀d²)
Now, we can see that E is inversely proportional to the square of d i.e.
E ∝ 1/d²
The electric field at P has some magnitude E. We now double the side length of the sheet to 2L while keeping the same amount of charge Q distributed over the sheet.
From the relationship of E with d, the magnitude of electric field at P will now have a quarter of its original magnitude which is;
E_new = E/4
Answer:
it comes from your knowledge and the information you have to get the reason why that is the answer so you are putting together things that you already know what the new information you have
Answer:
29 seconds
Explanation:
First we have a constant speed of 12 m/s and the distance of 240 m, so to find the time we can use the formula:
distance = speed * time
240 = 12 * time1
time1 = 20 seconds
Then, the speed decreases at 2 m/s2 until it reaches 2 m/s. So to find this time, we use this formula:
Final speed = inicial speed + acceleration * time
2 = 12 - 2 * time2
2*time2 = 10
time2 = 5 seconds.
Then, the speed increases from 2 m/s to 22 m/s with an acceleration of 5 m/s2, so we have:
Final speed = inicial speed + acceleration * time
22 = 2 + 5 * time3
5*time3= 20
time3 = 4 seconds
The total time is:
Total time = time1 + time2 + time3 = 20 + 5 + 4 = 29 seconds
