Students vary the load on a block and record the corresponding kinetic friction force…
PHYSICS · Single correct · CBSE · Physics · Laws of Motion · Laws of Motion
Problem
Students vary the load on a block and record the corresponding kinetic friction force using a force sensor. They plan to plot friction force (vertical axis) versus normal force (horizontal axis). Which statement best explains how the plot can be used to obtain the coefficient of kinetic friction?
(a) The reciprocal of the slope of the best-fit line equals the coefficient, since rearranging Fk=μkN gives μk=FkN.
(b) The slope of the best-fit line divided by g equals the coefficient, because the normal force is the weight mg.
(c) The slope of the best-fit line gives the coefficient, because kinetic friction is directly proportional to the normal force.
(d) The y-intercept of the best-fit line equals the coefficient, because it represents the friction force when the normal force is zero.