WAEC Physics 2010 Paper

Concept:Static friction is the force that opposes the start of motion between two surfaces in contact.Explanation:Static friction depends on the nature of the surfaces in contact, not on the area of contact.It acts before motion begins, so it does not depend on relative motion.Its maximum value is given by $f_s = \mu_s N$, where $\mu_s$ is the coefficient of static friction and $N$ is the normal reaction.On a horizontal surface, the normal reaction equals the weight of the body, i.e. $N = mg$.Therefore, static friction depends on the weight of the body.Answer:D. depends on the weight of the moving body