Explanation:
Since, it is given that one hand completes 3.19 vibrations in 8.46 sec. Therefore, in one second the number of vibrations will be as follows.

= 0.377 vibrations
Hence, frequency (f) = 0.38 Hz
Now, formula to calculate the speed is as follows.
v = 
or,
= 
= 1.57 cm
Thus, we can conclude that the wavelength is 1.57 cm.
Answer:
271.862 N/m
Explanation:
From Hook's Law,
mgh = 1/2ke²............... Equation 1
Where
m = mass of the ball, g = acceleration due to gravity, k = spring constant, e = extension, h = height fro which the ball was dropped.
Making k the subject of the equation,
k =2mgh/k²....................... Equation 2
Note: The potential energy of the ball is equal to the elastic potential energy of the spring.
Given: m = 60.3 g = 0.0603 kg, g = 9.8 m/s², e = 4.68317 cm = 0.0468317 m, h = 53.7 cm = 0.537 m
Substitute into equation 2
k = 2(0.0603)(9.8)(0.537)/0.048317²
k = 0.6346696/0.0023345
k = 271.862 N/m
I think is A or B it depends on like what the trying to answer
To solve this problem we will apply the concepts related to the Doppler effect. The Doppler effect is the change in the perceived frequency of any wave movement when the emitter, or focus of waves, and the receiver, or observer, move relative to each other. Mathematically it can be described as,

Here,
= Frequency of Source
= Speed of sound
f = Frequency heard before slowing down
f' = Frequency heard after slowing down
v = Speed of the train before slowing down
So if the speed of the train after slowing down will be v/2, we can do a system equation of 2x2 at the two moments, then,
The first equation is,



Now the second expression will be,



Dividing the two expression we have,

Solving for v, we have,

Therefore the speed of the train before and after slowing down is 22.12m/s
Answer:
a). Single replacement.
Explanation:
Because one element replaces another element in a compound