Answer:
n = 1.42
Explanation:
The refractive index for a medium is given by the ratio of the speed of light in vacuum to the speed of light in a medium.

So, the refractive index of the medium is 1.42.
Answer: The correct answer is "the speed of the wave becomes four times".
Explanation:
The relation between the speed, frequency and the wavelength is as follows:
v=f\lambda
Here, v is the speed of the wave, f is the frequency and \lambda is the wavelength.
The speed of the sound wave is directly proportional to the frequency.
In the given problem, if the speed of the sound wave is increased four times then the speed of the sound becomes four times.
Therefore, the speed of the sound wave becomes four times.
Answer:
Mass = 386 kg
Explanation:
<u><em>Density = Mass / Volume</em></u>
Mass = Density × Volume
Where D = 19300 kg/m³ , V = 0.02 m³
<em>Putting the given in the above formula</em>
Mass = 19300 × 0.02
Mass = 386 kg
Answer:
If an object has a fast velocity, the dots on a ticker tape diagram will be far apart.
Answer:

Explanation:
Given that

From the diagram

By differentiating with time t

When x= 10 m

θ = 64.53°
Now by putting the value in equation



Therefore rate of change in the angle is 0.038\ rad/s