Answer
The net force applied on the body is 50 N.
Work Step by Step
Given that the block of weighs 10 kg on a slant with an inclination of $\theta=30^{\circ}$
The net resultant on the block due to gravitation is $R=10\times10=100N$
We break this into components:
i) component applied normal to the block surface: $100\cos30^{\circ}$
ii) component opposite to the force: $100\sin30^{\circ}=50$
So, the net force applied on the body is 50 N.