Answer:
1) 341 Hz
Explanation:
When a string vibrates, it can vibrate with different frequencies, corresponding to different modes of oscillations.
The fundamental frequency is the lowest possible frequency at which the string can vibrate: this occurs when the string oscillate in one segment only.
If the string oscillates in n segments, we say that it is the n-th mode of vibration, or n-th harmonic.
The frequency of the n-th harmonic is given by

where
n is the number of the harmonic
is the fundamental frequency
Here we have:
is the frequency of the 3rd harmonic
So the fundamental frequency is

And so, the frequency of the 2nd harmonic is:

Answer:
1.02 seconds
Explanation:
Initial velocity = u = 5 m/s
t = Time taken
s = Displacement travelled = 0
a = Acceleration due to gravity = -9.81 m/s² (negative sign due to direction)
Equation of motion

So, time taken to return to its initial position is 1.02 seconds
If a galaxy is located 200 million light years from Earth, you can conclude that t<span>he light will take 200 million years to reach Earth. </span>
The train would need the greatest amount of force due to weight! If you think of it, a baseball won't need much force to stop it, but if you have a heavy train, it will need excessive force to stop the train. The answer would be #3
I hope this answer helps!
Sorry if it doesn't make sense, as I don't know that much about physics! I am just thinking of what makes sense.