We want to find how far was the slingshot stretched. We will see that it was stretched 10 centimeters approx.
Remember that for a spring of constant K, the elastic potential energy is given by:
[tex]P = \frac{1}{2}K*X^2[/tex]
Where X is how far the spring is stretched.
Now, we can think of a slingshot as a spring, we know that the constant is:
And that the elastic potential energy is:
Now we can just replace these two in the above equation to find the value of X:
[tex]P = \frac{1}{2}K*X^2\\\\X = \sqrt{2*P/K} = \sqrt{2*(1.4*10^2 Nm)/(3.0* 10^4 N/m)} = 0.1 m[/tex]
So the slingshot was stretched 10cm approx.
If you want to learn more about springs, you can read:
https://brainly.com/question/2901244