Answer:
The force is 
Explanation:
The diagram for this question is shown on the first uploaded image
At Equilibrium the summation of the of force on the vertical axis is zero
i.e 
=> 
is the is the speed of water at the nozzle which can be mathematically evaluated as

substituting
for R and
for


is the is the speed of water at the pipe which can be mathematically evaluated as

substituting
for R and
for


is he density of water with value 
Substituting values into the equation above


At Equilibrium the summation of the of force on the horizontal axis is zero
i.e 
=> 
Since The speed at both A and B nozzle are the same then
remains the same
Substituting values

=> 
Hence the force acting on the flange bolts required to hold the nozzle in place is



To solve this exercise it is necessary to apply the equations related to the magnetic moment, that is, the amount of force that an image can exert on the electric currents and the torque that a magnetic field exerts on them.
The diple moment associated with an iron bar is given by,

Where,
Dipole momento associated with an Atom
N = Number of atoms
y previously given in the problem and its value is 2.8*10^{-23}J/T


The number of the atoms N, can be calculated as,

Where
Density
Molar Mass
A = Area
L = Length
Avogadro number


Then applying the equation about the dipole moment associated with an iron bar we have,



PART B) With the dipole moment we can now calculate the Torque in the system, which is



<em>Note: The angle generated is perpendicular, so it takes 90 ° for the calculation made.</em>
Let the mass of 2500 kg car be
and it's velocity be
and the mass of 1500 kg car be
and it's velocity be
.
After the bumping the mass be M and it's velocity be V.
By law of conservation of momentum we have

2500 * 5 + 1500 * 1=4000 * V
V = 14000/4000 = 7/2 = 3.5 m/s
So the velocity of the two-car train = 3.5 m/s
Year 1972
if I'm not wrong :)
b. the forces of attraction among them limit their motion.