A. always positive
B. always negative
C. positive only for small frictional force
D. positive only for large frictional force
Correct Answer: always negative ✔
Last Updated: February 11, 2021
A. always positive
B. always negative
C. positive only for small frictional force
D. positive only for large frictional force
Correct Answer: always negative ✔
Last Updated: February 11, 2021