It is required an infinite work. The additional electron will never reach the origin.
In fact, assuming the additional electron is coming from the positive direction, as it approaches x=+1.00 m it will become closer and closer to the electron located at x=+1.00 m. However, the electrostatic force between the two electrons (which is repulsive) will become infinite when the second electron reaches x=+1.00 m, because the distance d between the two electrons is zero:

So, in order for the additional electron to cross this point, it is required an infinite amount of work, which is impossible.
Answer:
The resulting, needed force for equilibrium is a reaction from a support, located at 2.57 meters from the heavy end. It is vertical, possitive (upwards) and 700 N.
Explanation:
This is a horizontal bar.
For transitional equilibrium, we just need a force opposed to its weight, thus vertical and possitive (ascendent). Its magnitude is the sum of the two weights, 400+300 = 700 N, since weight, as gravity is vertical and negative.
Now, the tricky part is the point of application, which involves rotational equilibrium. But this is quite simple if we write down an equation for dynamic momentum with respect to the heavy end (not the light end where the additional weight is placed). The condition is that the sum of momenta with respect to this (any) point of the solid bar is zero:

Where momenta from weights are possitive and the opposed force creates an oppossed momentum, then a negative term. Solving our unknown d:

So, the resulting force is a reaction from a support, located at 2.57 meters from the heavy end (the one opposed to the added weight end).
As per the question the distance travelled by a car is 28.4 inch.
we are asked to determine the conversion factor in centimeter which when multiplied with 28.4 inch will give a unit.
we know that one inch =2.54 centimeter.
Hence 28.4 inch = 2.54 ×28.4 cm
=72.136 cm.
Now we have to determine the conversion factor .The multiplication factor is calculated as 
[p is the multiplication factor.]
Hence the multiplication factor is 72.137 cm which will give unit conversion when multiplied with 28.4 inch.
magnetic field due to a finite straight conductor is given by

here since it forms an equilateral triangle so we will have

also the perpendicular distance of the point from the wire is

now from the above equation magnetic field due to one wire is given by



now since in equilateral triangle there are three such wires so net magnetic field will be

Answer:
Note: Angular momentum is always conserved in a collision.
The initial angular momentum of the system is
L = ( It ) ( ωi )
where It = moment of inertia of the rotating circular disc,
ωi = angular velocity of the rotating circular disc
The final angular momentum is
L = ( It + Ir ) ( ωf )
where ωf is the final angular velocity of the system.
Since the two angular momenta are equal, we see that
( It ) ( ωi ) = ( It + Ir ) ( ωf )
so making ωf the subject of the formula
ωf = [ ( It ) / ( It + Ir ) ] ωi
Explanation: