Answer:When you place like poles of two magnets near each other (north to north or south to south), they will repel each other
Explanation:
Every magnet has both a north and a south pole. When you place the north pole of one magnet near the south pole of another magnet, they are attracted to one another. When you place like poles of two magnets near each other (north to north or south to south), they will repel each other.
Answer:
The recoil speed of the man and rifle is .
Explanation:
The expression for the force in terms of mg is as follows;
F=mg
Here, m is the mass and acceleration due to gravity.
Rearrange the expression for mass.
Calculate the combined mass of the man and rifle.
Put .
The expression for the conservation of momentum is as follows as;
Here, is the mass of the man and rifle, is the mass of the rifle, are the initial velocities of the man and bullet and are the final velocities of the man and rifle and rifle.
It is given in the problem that a rifle with a weight of 25 N fires a 4.5-g bullet with a speed of 240 m/s.
Convert mass of rifle from gram to kilogram.
Put , , , and .
Therefore, the recoil speed of the man and rifle is .
D) chemical change, irreversible.
This is because if two liquids made a solid when mixed together, it was most likely a chemical change (especially is bubbles were produced!), and a chemical change is permanent!
Answer:
Explanation:
In the given case for destructive interference , the condition is,
path difference = (2n+1)λ /2 where n is an integer and λ is wavelength
2 μ d = (2n+1)λ /2
Putting λ = 653 nm
for minimum thickness n = 0
2 μ d = 653 / 2 nm
= 326.5 nm
For constructive interference the condition is
2 μ d = n λ₁
326.5 nm = n λ₁
λ₁ = 326.5 / n
For n = 1
λ₁ = 326.5 nm ,
or , 326.5nm .
Longest wavelength possible is 326.5
(a) The electron kinetic energy is
which can be converted into Joule by keeping in mind that
So that we find
The kinetic energy of the electron is related to its momentum p by:
where m is the electron mass. Re-arranging the equation, we find
And now we can use De Broglie's relationship to find its wavelength:
where h is the Planck constant.
(b) By using the same procedure of part (a), we can convert the photon energy into Joules:
The energy of a photon is related to its frequency f by:
where h is the Planck constant. Re-arranging the equation, we find
And now we can use the relationship between frequency f, speed of light c and wavelength
of a photon, to find its wavelength: