This question can be easily solved by using the law of conservation of energy.
The work done by the friction is "9.9 J".
The law of conservation of energy applied to this condition gives the following equation:
[tex]Potential\ Energy\ Lost\ by\ Block = Energy\ Stored\ by\ Spring\ +\ Work\ done\ by\ friction\\\\mgh = \frac{1}{2}kx^2\ +\ W[/tex]where,
W = Work done by friction = ?
m = mass of the block = 4.8 kg
g = acceleration due to gravity = 9.81 m/s²
h = height = 0.52 m
k = spring constant = 2000 N/m
x = compression distance = 12.1 cm = 0.121 m
Therefore,
[tex](4.8\ kg)(9.81\ m/s^2)(0.52\ m)=\frac{1}{2}(2000\ N/m)(0.121\ m)^2+W\\W = 24.5\ J - 14.6\ J[/tex]
W = 9.9 J
Learn more about the law of conservation of energy here:
brainly.com/question/20971995?referrer=searchResults
The attached picture explains the law of conservation of energy.