Answer:
yeah I'm Pretty sure it's b
That's the wave's ' period '.
It's the reciprocal of the wave's frequency.
E=hf
E=6.626e-34[Js]•1500e3[Hz]=9.939e-28[J]
For eV divide this by electron charge
9.939e-28[J]/1.6022e-19[C/e]=
6.203e-9eV
Answer:
The second law of a vibrating string states that for a transverse vibration in a stretched string, the frequency is directly proportional to the square root of the string's tension, when the vibrating string's mass per unit length and the vibrating length are kept constant
The law can be expressed mathematically as follows;

The second law of the vibrating string can be verified directly, however, the third law of the vibrating string states that frequency is inversely proportional to the square root of the mass per unit length cannot be directly verified due to the lack of continuous variation in both the frequency, 'f', and the mass, 'm', simultaneously
Therefore, the law is verified indirectly, by rearranging the above equation as follows;

From which it can be shown that the following relation holds with the limits of error in the experiment
m₁·l₁² = m₂·l₂² = m₃·l₃² = m₄·l₄² = m₅·l₅²
Explanation:
Answer:
The free body diagram of John is shown in the attached figure (in the FBD john's mass is supposed to be concentrated at his center of mass and FBD is made of center of mass)
b) As shown in the FBD the ground reaction forces are:
i) In X direction 
ii) In Y direction 
c) The respective accelerations in x and y direction's is calculated by newton's second law as indicated under
