Describe how varying the incline plane angle affects the force

the force increases as the angle increases

Explanation:

If we assume the incline plane is frictionless, the only force acting on an object on the incline plane is the force of gravity:

where m is the mass and g the acceleration due to gravity.

However, the actual force that makes the object sliding down along the incline is not the gravity itself, but the component of the force of gravity parallel to the surface of the incline, which is given by

where is the angle of the incline.

Therefore, we see that as the angle of the incline increases, the force on the object increases.