If coefficient of friction is 0.5 , Applied force on a block is 49 N and mass of block is 10 kg then acceleration is ?

As we can see that two forces are acting on the block : 49 N force and friction force (f)
We have = 0.5
f=N
Where N = mg
= 0.51010=50N
So, net force acting on the block in horizontal direction = 50N-49 N = 1 N

So, Acceleration of the block = Net force / mass of block = 1 N/10 kg = 0.1 meter per second square.
I hope that's clear.