Question

While sitting in a lounge chair with the back inclined at an angle of 10 degrees from the vertical, you tuck a pillow between your head and the chair. Then you lower the chair back to 40 degrees and doze with the pillow in place. How has the net force on the pillow changed?

Answer 1

Less compression in your neck and more weight of your head on the pillow.

Answer 2

the key is "net force".
in both cases acceleration is zero. therefore net force is also zero. Newton's second law, Fnet = mass * accel