I see the word "when..." kind of fading out at the end of the first line.
Whatever comes after it may be important.
If you're just supposed to copy the expression into the box,
then the problem is that you left the 'e' out of it.
I'm guessing that you're supposed to enter whatever the expression becomes
when either N₀ or ' t ' has some special value that's in the first line.
Just taking a wild guess here . . . . .
If it's "Enter the expression ..... , when t=0 ." ,
then the correct answer in the box is N₀ .
But that's just a wild guess. As I pointed out, you cut off
the picture in the middle of the word 'when', and I've got
a hunch that there's something important after it.
Answer:

Explanation:
Given that
Length= 2L
Linear charge density=λ
Distance= d
K=1/(4πε)
The electric field at point P



So

Now by integrating above equation

Answer:
The rise from A to B is 0.887
Solution:
As per the question:
The following reading of an inverted staff is given as:
A = 2.915
B = -2.028
Here, for inverted staff, the greater reading shows greater elevation and lesser reading shows lower elevation.
Thus
The rise from A to B is given as:
A - B = 2.915 - 2.028 = 0.887
Speed v = initial speed u + acceleration a x time t
v=u+at = 2 + 4*3 = 14 m/s
Answer:
The potential energy stored in the spring is 0.018 J.
Explanation:
Given;
spring constant, k = 90 N/m
extension of the spring, x = 2 cm = 0.02 m
The potential energy stored in the spring is calculated as;
U = ¹/₂kx²
where;
U is the potential energy stored in the spring
Substitute the given values in the equation above;
U = ¹/₂ x 90 N/m x (0.02 m)²
U = 0.018 J
Therefore, the potential energy stored in the spring is 0.018 J.