To develop this problem it is necessary to apply the concept of Frequency based on speed and wavelength.
According to the definition the frequency can be expressed as

Where,
v = Velocity
Wavelength
Our value are given by,
v = 345m/s

Replacing


Therefore the frequency of the tuning fork is 547.61Hz
Answer: D
1200
Explanation:
Song 1 is spotted with a cube sign.
At 3 minute, trace the spot to the vertical axis. And you will notice that it a little bit above 10.
Since it is above 10, let assume it is equal to 12.
The number of song downloaded are in hundreds. Therefore, multiply the 12 by 100
12 × 100 = 1200 downloads
Approximately, song 1 has 1200 downloads at minute 3
The sun is a clear example of objects releasing radiation in nature
Answer:

Explanation:
Given that
For straight wire
Charge density= λ
For hollow metal cylinder
Charge density=2 λ
We know that electric filed for wire given as


Now the electric filed due to hollow metal cylinder


Now by considering the Gaussian surface r<R then only electric fild due to wire will present.So
At r<R

We can apply the law of conservation of energy here. The total energy of the proton must remain constant, so the sum of the variation of electric potential energy and of kinetic energy of the proton must be zero:

which means

The variation of electric potential energy is equal to the product between the charge of the proton (q=1eV) and the potential difference (

):

Therefore, the kinetic energy gained by the proton is

<span>And since the initial kinetic energy of the proton was zero (it started from rest), then this 1000 eV corresponds to the final kinetic energy of the proton.</span>