Physics about spring and work??

Question

given m=2.5 kg slides into spring k=320 n/m. when the block stops, it has compressed the spring by 7.5 cm. the coeficient kinetic friction between the block and the floor is 0.25.

QUESTION: While the block is in contact with the spring and being brought to rest,

(a) work done by spring force?

(b)increase in thermal energy of the block-floor system?

(c)what is the block's speed just as it reaches the spring?

Answer 1

a) E= Kx^2/2

b) E= FX = coeficient kinetic friction * mass * x

c) E=mv^2/2 = Kx^2/2+Fx