Answer:
the answer is A.
Explanation:
Using the laws of newton:
∑F = ma
where ∑F is the sumatory of forces acting in the system, m the mass and a the acelertion of the system.
Then, if the block is moving with constant velocity, its aceleration is equal to 0, so:
∑F = m(0)
∑F = 0
It means that:
F - = 0
where F is the force applied and is the friction force. Replacing the value of F, we get:
310N - = 0
Finally, solving for :
Answer:
X-rays travel through space faster than radio waves.
Explanation:
Electromagnetic waves consist of oscillations of the electric and the magnetic field in a plane perpendicular to the direction of motion the wave.
All electromagnetic waves travel in a vacuum always at the same speed, the speed of light, whose value is:
Electromagnetic waves are classified into 7 different types, according to their wavelength/frequency. From shortest to longest wavelength (and so, from highest to lowest frequency), we have:
Gamma rays
X rays
Ultraviolet
Visible light
Infrared radiation
Microwaves
Radio waves
Now we can analyze the 4 statements:
X-rays and radio waves are both forms of light, or electromagnetic radiation --> TRUE. They are both types of electromagnetic waves.
X-rays have higher frequency than radio waves. --> TRUE, as we can see from the table above.
X-rays have shorter wavelengths than radio waves. --> TRUE, as we can see from the table above.
X-rays travel through space faster than radio waves. --> FALSE: all electromagnetic waves travel in space at the same speed, the speed of light.
Answer:
Explanation:
From the second law of Newton movement laws, we have:
, and we know that a is the acceleration, which definition is:
, so:
The next step is separate variables and integrate (the limits are at this way because at t=0 the block was at rest (v=0):
(This is the indefinite integral), the definite one is: