The block travels down the inclined plane

And after travelling 1.6 m, it hits the spring.

Let's assume that it compresses spring by x meters.

Initial KE = 0 (as it start from rest)

Final KE = 0 (as it stops after compressing the spring)

Now,

i) Work done by gravity $= mgh \\ = 30 * (1.6+x) \sin30 \\ = 24 + 15x $

ii) Work by frictional force $= -µNS \\ = 0.25 * (30 \cos30)(1.6 + x) \\ = - 10.39 - 6.495x $

iii) Work by spring force $= (1/2)*K*(x12 - x22) \\ = (1/2)*1000(0 - x2) \\ = - 500 x2 $

Now, applying WEP

$0 = 24 + 15x - 10.39 - 6.495x - 500 x2 \\ 0 = -500x2 + 8.505x + 13.61 $

Solving quadratic, we get

$X= 0.1737 m $

The maximum compression of spring is $0.1737 m $