Matter. I don't really know how to explain it. Sorry. But anyways, Hope this helps!
The top row of boxes is " F O R C E " .
Answer:
Friction is a force that holds back the movement of a sliding object.
Explanation:
The two types of friction: Static friction and Kinetic friction. Static friction operates between two surfaces that aren't moving relative to each other, while kinetic friction acts between objects in motion.
Answer:
A. 20 N
Explanation:
the weight of book is 2×10= 20N