A body of mass 20 kg is released from rest at the top of a rough slope which is inclined at 30 degree to the horizontal. If the body accelerates down the slope at 3m/s^2, find the resistance to motion experienced by the body. ( Assume this resistance to be constant throughout)

My answer: Forceof body= mg= 20x9.8

= 196 N at 30 degree

Force parallel to the plane = 196x sin30= 98N

Fnet= Fp-Fr= ma

98-Fr= 20x-3

--Fr= -60-98

= -158N

Please review and correct me. Thank you very much for your time and help.