Contact forces are actions that take place only when objects are touching each other. Non-contact forces are actions that can take place whether objects are touching or not. Which of the following is a non-contact force? A. impact force B. gravity C. air resistance D. pushing

I am pretty sure it is Gravity..

Step-by-step explanation:

< coa = 150 ( given)

as ba and bc are tangents

so oc and oa is perpendicular to cb and ab respectively because in circle normal passes through centre

so in quadrilateral oabc

< coa + < oab + < ocb + < abc = 360

150 +90+90 + < abc = 360

330 + < abc = 360

< abc = 360 -330 = 30

so < abc = 30

⭐dhruv⭐

- 70

this is the answer for you hope it