Explanation:
Electromagnetism is a branch of physics involving the study of the electromagnetic force, a type of physical interaction that occurs between electrically charged particles. The electromagnetic force is carried by electromagnetic fields composed of electric fields and magnetic fields, and it is responsible for electromagnetic radiation such as light.
Answer:
The discharge of a capacitor changes the direction of the current
Explanation:
Capacitor is used to store charges. Changing and discharging a capacitor changes the direction of the current.
When a capacitor is charging, current flows towards the positive plate and away from the negative plate. When the capacitor is discharging, current flows away from the positive and flows towards the negative plate, in the opposite direction. During these two processes (charging and discharging), it can be seen that the direction of the current is changed.
Therefore, the discharge of a capacitor changes the direction of the current
Answer:
μ = 0.0315
Explanation:
Since the car moves on a horizontal surface, if we sum forces equal to zero on the Y-axis, we can determine the value of the normal force exerted by the ground on the vehicle. This force is equal to the weight of the cart (product of its mass by gravity)
N = m*g (1)
The friction force is equal to the product of the normal force by the coefficient of friction.
F = μ*N (2)
This way replacing 1 in 2, we have:
F = μ*m*g (2)
Using the theorem of work and energy, which tells us that the sum of the potential and kinetic energies and the work done on a body is equal to the final kinetic energy of the body. We can determine an equation that relates the frictional force to the initial speed of the carriage, so we will determine the coefficient of friction.
where:
vf = final velocity = 0
vi = initial velocity = 85 [km/h] = 23.61 [m/s]
d = displacement = 900 [m]
F = friction force [N]
The final velocity is zero since when the vehicle has traveled 900 meters its velocity is zero.
Now replacing:
(1/2)*m*(23.61)^2 = μ*m*g*d
0.5*(23.61)^2 = μ*9,81*900
μ = 0.0315
To solve this problem we will use the concept related to electrons in a box which determines the energy of an electron in that state.
Mathematically this expression is given by,
Where,
m = mass of an electron
h = Planck's constant
n = is the integer number of the eigenstate
L = Quantum well width
The change in energy must be given in state 1 and 2, therefore
Replacing we have:
Therefore the correct answer is C.
Answer:
b. The reflection of light from a smooth surface is called specular reflection.
c. The reflection of light from a rough surface is called diffuse reflection.
Explanation:
a. The angle of incidence is equal to the angle of reflection only when a ray of light strikes a plane mirror.
This is wrong: Based on law of reflection "The angle of incidence is equal to the angle of reflection when light strikes any plane surface" examples plane mirrors, still waters, plane tables, etc
b. The reflection of light from a smooth surface is called specular reflection.
This is correct
c. The reflection of light from a rough surface is called diffuse reflection.
This is correct
d. For diffuse reflection, the angle of incidence is greater than the angle of reflection.
This is wrong: the angle of incident is equal to angle of reflection. The only difference between this type of reflection and specular reflection, is that the normal for diffuse reflection is not parallel to each due to the rough surface in which the light incidents.
For specular reflection, the angle of incidence is less than the angle of reflection.
This is wrong: the angle of incident is equal to angle of reflection
