A box is pushed horizontally with constant speed across a rough horizontal surface.
1 answer:
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Answer:
It will not change
Explanation:
The period of oscillation of a mass-spring system is given by
where
T is the period
m is the mass hanging on the spring
k is the spring constant
As we see from the formula, the period of oscillation does not depend on the amplitude of the motion: therefore, if we change the amplitude, the time for one oscillation will not change.
Answer:
C. It speeds up, and the angle increases
Explanation:
We can answer by using the Snell's law:
where
are the refractive index of the first and second medium
is the angle of incidence (measured between the incident ray and the normal to the surface)
is the angle of refraction (measured between the refracted ray and the normal to the surface)
In this problem, light moves into a medium that has lower index of refraction, so
We can rewrite Snell's law as
and since
this means that
which implies
so, the angle increases.
Also, the speed of light in a medium is given by
where c is the speed of light and v the refractive index: we see that the speed is inversely proportional to n, therefore the lower the index of refraction, the higher the speed. So, in this problem, the light will speed up, since it moves into a medium with lower index of refraction.