Q. A block of mass 4 kg is kept on a rough horizontal surface. The coefficient of static friction is 0.8. If a force of 19 N is applied on the block parallel to the floor, then the force of friction between the block and floor is
A) 32 N
B) 18 N
C) 19 N
D) 9.8 N
Explanation
(a) $f = \mu mg = 0.8 \times 4 \times 10 = 32$ N
Applied force $F < f$ therefore, answer will be (a)
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.