Is that a question? .
..............................
Answer:
0.776 m far Pinhole should be placed before the viewing screen
Explanation:
For circular aperture of diameter D will have a bright central maximum of diameter, width is given by

where
is wavelength of helium neon laser = 633 nm, D=10.cm, w=0.12 mm
Pinhole should be placed before the viewing screen is

2) What must be connected for an electrical current to flow in a simple current?
<em>d.moving magnets,conductors, load to do work
</em>
here moving magnets will work as generator and conductors is used as connectors.
5)What is the purpose of a load in a circuit?
<em>c.provide resistance to keep the voltage strong
</em>
Load will provide the resistance to the circuit and help to build the voltage across it
6) What cause an electric current from a generator
<em>d.Magnets and conducting wires move near each other
</em>
here when magnets move near wires then it will induce the electric current and behaves like generators
7) What do all generators have in common
<em>b.they transform mechanical into electrical energy
</em>
They have magnets and rotating coils which will convert magnetic energy to electrical energy
8) How can we measure electrical current
<em>b.the pressure force is voltage;the # of electrons moving is amperes
</em>
this voltage and number of electrons will help to calculate current
Answer:
If the rifle is held loosely away from the shoulder, the recoil velocity will be of -8.5 m/s, and the kinetic energy the rifle gains will be 81.28 J.
Explanation:
By momentum conservation, <em>and given the bullit and the recoil are in a straight line</em>, the momentum analysis will be <em>unidimentional</em>. As the initial momentum is equal to zero (the masses are at rest), we have that the final momentum equals zero, so

now we clear
and use the given data to get that

<em>But we have to keep in mind that the bullit accelerate from rest to a speed of 425 m/s</em>, then <u>if the rifle were against the shoulder, the recoil velocity would be a fraction of the result obtained</u>, but, as the gun is a few centimeters away from the shoulder, it is assumed that the bullit get to its final velocity, so the kick of the gun, gets to its final velocity
too.
Finally, using
we calculate the kinetic energy as
