Answer:
Magnetic field, 
Explanation:
Given that,
Velocity of electron, 
It enters a region of space where perpendicular electric and a magnetic fields are present.
Magnitude of electric field, 
We need to find the magnetic field will allow the electron to go through the region without being deflected.
Magnetic force on the electron,
.......(1)
Electric force on the electron, F = q E........(2)
From equation (1) and (2) we get:



B = 0.0002 T
or

Hence, this is the required solution.
<span>In a 2-dimensional coordinate system, the x- and y-axes
are typically perpendicular to each other. (C) </span>
Answer:
A. The wavelengths of the new sound waves are longer
Explanation:
This is the Doppler effect which can be best illustraded for the case of a siren of an ambulance approaching us having a greater frequency and getting lower in frequency and deeper as the ambulance passes us.
Since the wavelength is inversely proportional to the frequency it follows the wavelengths are longer when the frequency decreases lowering its pitch and getting deeper.
Answer: 117.6N
Explanation:
By the second Newton's law, we know that:
F = m*a
F = force
m = mass
a = acceleration
We know that in the surface of the Earth, the gravitational acceleration is g = 9.8m/s^2.
Then we just can input that acceleration in the above equation, and also replace m by 12kg, and find that the force due the gravity is:
F = 12kg*9.8m/s^2 = 117.6N
To develop this problem it is necessary to apply the Rayleigh Criterion (Angular resolution)criterion. This conceptos describes the ability of any image-forming device such as an optical or radio telescope, a microscope, a camera, or an eye, to distinguish small details of an object, thereby making it a major determinant of image resolution. By definition is defined as:

Where,
= Wavelength
d = Width of the slit
= Angular resolution
Through the arc length we can find the radius, which would be given according to the length and angle previously described.
The radius of the beam on the moon is

Relacing 


Replacing with our values we have that,


Therefore the diameter of the beam on the moon is



Hence, the diameter of the beam when it reaches the moon is 7361.82m