Answer:
24 m
Explanation:
By applying the law of conservation of energy.
K.E = P.E
[tex]\dfrac{1}{2}kx^2 = mgh[/tex]
By rearrangement;
[tex]\dfrac{k}{m} = \dfrac{2*g*h}{x^2}[/tex]
where;
k = spring constant
m = mass of pebble
h = height reached
x = stretched length
[tex]\dfrac{k}{m} = \dfrac{2*9.8*6}{(20 \times 10^{-2})^2}[/tex]
[tex]\dfrac{k}{m} =0.2940 \times 10^4[/tex]
Since the drag force is negligible;
[tex]\dfrac{1}{2}kx^2 = mgh[/tex]
[tex]h = \dfrac{k}{m}\dfrac{x^2}{g}[/tex]
[tex]h = \dfrac{1}{2}\times 0.2940 \times 10^4 \times \dfrac{(40\times 10^{-2})^2}{9.8}[/tex]
h = 24 m
