Answer:
After 4 s of passing through the intersection, the train travels with 57.6 m/s
Solution:
As per the question:
Suppose the distance to the south of the crossing watching the east bound train be x = 70 m
Also, the east bound travels as a function of time and can be given as:
y(t) = 60t
Now,
To calculate the speed, z(t) of the train as it passes through the intersection:
Since, the road cross at right angles, thus by Pythagoras theorem:


Now, differentiate the above eqn w.r.t 't':


For t = 4 s:

The capacitance of a capacitor is the ratio of the stored charge to its potential difference, i.e.
C = Q/ΔV
C is the capacitance
Q is the stored charge
ΔV is the potential difference
Rearrange the equation:
ΔV = Q/C
We also know the capacitance of a parallel-plate capacitor is given by:
C = κε₀A/d
C is the capacitance
κ is the capacitor's dielectric constant
ε₀ is the electric constant
A is the area of the plates
d is the plate separation
If we substitute C:
ΔV = Qd/(κε₀A)
We assume the stored charge and the area of the plates don't change. Then if we double the plate spacing, i.e. we double the value of d, then the potential difference ΔV is also doubled.
I think its a tbh bc it seems to be the best answer out of a b c and d
(a) The plastic rod has a length of L=1.3m. If we divide by 8, we get the length of each piece:

(b) The center of the rod is located at x=0. This means we have 4 pieces of the rod on the negative side of x-axis, and 4 pieces on the positive side. So, starting from x=0 and going towards positive direction, we have: piece 5, piece 6, piece 7 and piece 8. Each piece is 0.1625 m long. Therefore, the center of piece 5 is at 0.1625m/2=0.0812 m. And the center of piece 6 will be shifted by 0.1625m with respect to this:

(c) The total charge is

. To get the charge on each piece, we should divide this value by 8, the number of pieces:

(d) We have to calculate the electric field at x=0.7 generated by piece 6. The charge on piece 6 is the value calculated at point (c):

If we approximate piece 6 as a single charge, the electric field is given by

where

and d is the distance between the charge (center of piece 6, located at 0.2437m) and point a (located at x=0.7m). Therefore we have

poiting towards the center of piece 6, since the charge is negative.
(e) missing details on this question.
Protons
Explanation:
In a neutral atom, the number of electrons equals the number of protons in the atom.
- Electrons are the negatively charge particles in an atom
- Protons carry positive charge.
- Neutrons do not carry any charges.
Protons and neutrons are contained in the nucleus of an atom they determine the mass number of the atom.
In a neutral atom, the number of protons and electrons must be the same.
A charge atom called an ion is one that has lost or gained electrons.
Learn more:
Cations brainly.com/question/8698247
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