Answer:
l think C am not pretty show
Answer:
the oscillations of the electrons must be in the 10⁸ Hz = 100 MHz range
Explanation:
The speed of a wave of radio, television, light, heat, all are manifestations of electromagnetic waves that are oscillations of electric and magnetic fields that support each other, the speed of all these waves is the same and the vacuum is equal to c = 3 108 m / s
All waves have a relationship between the speed of the wave, its frequency and wavelength
c = λ f
f = c /λ
for this case lam = 1 m
f = 3 10⁸/1
f = 3 10⁸ Hz
the oscillations of the electrons must be in the MHz range
It should be clarified that the speed of light in air is a little lower
n = c / v
v = c / n
the refractive index of vacuum is n = 1 and the refractive index of air is n = 1.000002
Answer:
Friction between the box and the floor is 25N to the left
Explanation:
There are two forces acting on the box along the horizontal direction:
- The force of push applied by the worker, in the forward direction, F
- The force of friction,
, acting in the opposite direction (backward)
So the net force acting on the box is

According to Newton's second law of motion, the net force on an object is equal to the product between its mass (m) and its acceleration (a), so we can write:

And so

However, in this case the box is moving at constant speed; this means that its acceleration is zero:

Therefore we have:

Which means

And since we are told that

This means that the force of friction is also 25 N:

Answer:
An interference pattern.
Explanation:
When we have two light source of the same frequency turned on close to each other, the light emitted by them will interfere since light is also a wave. This means that an interference pattern will appear in a screen put ahead of them, that is, bands of light and darkness where the waves are interfering constructively and destructively.
Answer:
F= 5195.625 N
Explanation:
To obtain the force needed to hold the child, we need to know the aceleration in which the car is breaking.
Aceleration is equal to velocity divided by the time of breaking
In international system, velocity [m/s] is
v= (62 mi/h)*(1609 m/mi)*(1 h/3600 s)
v= 27.71 m/s
Now, we part the velocity by the time that is 0.08 seconds
a= v/t= (27.71 m/s)/(0.08 s)
a= 346.375 m/
The force in agreement with the Newton's second law is
F=m*a = 15 Kg*346.375 m/
F= 5195.625 N
(Note: 1 N = 1 Kg*m/
)