Answer:
Stretch can be obtained using the Elastic potential energy formula.
The expression to find the stretch (x) is 
Explanation:
Given:
Elastic potential energy (EPE) of the spring mass system and the spring constant (k) are given.
To find: Elongation in the spring (x).
We can find the elongation or stretch of the spring using the formula for Elastic Potential Energy (EPE).
The formula to find EPE is given as:

Rewriting the above expression in terms of 'x', we get:

Example:
If EPE = 100 J and spring constant, k = 2 N/m.
Elongation or stretch is given as:

Therefore, the stretch in the spring is 10 m.
So, stretch in the spring can be calculated using the formula for Elastic Potential Energy.
I'm pretty sure its transverse waves
I'm not sure I completely understand the expression you want evaluated.
It looks like a fraction with the same exact thing in both the numerator and the denominator. A fraction like that always boils down to ' 1 '.
C would be the right answer edu
Answer:
the best graph to find the acceleration is v-t since calculating the slope averages the different experimental errors.
Explanation:
The different graphics depending on time give various information, let's examine what we can get from some
Graph of x -t. from this graph we can obtain the speed through the slope, but the acceleration is not directly obtainable
v-t chart. We can get the acceleration not through the slope and the distance traveled by the area under the curve. Obtaining acceleration is very accurate since it is an average that avoids possible errors in measurements. This is the best graph to find the acceleration
Graph of a-t In this graph the acceleration is a point on the Y axis, it gives some errors because it depends strongly on the possible experimental errors.
In conclusion, the best graph to find the acceleration is v-t since calculating the slope averages the different experimental errors.