Friction

Three blocks with masses $m_1$, $m_2$, and $m_3$ are connected by ropes and pulleys as shown. Block 2 rests on a horizontal table. Assume the ropes and pulleys are massless and frictionless, and that $m_3 > m_1$. When the system is released from rest, it accelerates with a magnitude $a$.

As shown in the figure, two books, A and B, are interleaved page by page. The coefficient of static friction between pages is $\mu = 0.3$. The mass of each page is $m = 5$ g, and each book has $N=200$ pages. Book A is held stationary. A horizontal force $F$ is applied to pull out book B.

A block of mass $m$ is pushed along a horizontal floor by a constant applied force of magnitude $F$. The block starts from rest and its speed increases linearly with time, reaching a speed $v_s$ at time $t_s$.

A wedge of inclination angle $\theta$ and mass $m$ is placed on a horizontal table. An object, also of mass $m$, is placed on the inclined surface of the wedge. The coefficient of friction between the object and the wedge, and between the wedge and the table, is $\mu$.

Block B, of weight $W_B$, rests on a horizontal table. The coefficient of static friction between the block and the table is $\mu_s$. A system of cords connects block B, a hanging block A of weight $W_A$, and a wall, with one cord making an angle $\theta$ with the horizontal. The system is in static equilibrium.

Three crates with masses $m_1$, $m_2$, and $m_3$ are being pushed over a floor by a horizontal force $\vec{F}$ applied to crate 1. The coefficient of kinetic friction between the floor and each crate is $\mu_k$.

A block of mass $m_A$ on an inclined plane at angle $\theta$ is connected by a rope over a frictionless, massless pulley to a hanging block of mass $m_B$. The coefficients of static and kinetic friction between block A and the incline are $\mu_s$ and $\mu_k$. The positive direction is defined as up the incline, represented by the unit vector $\hat{i}$.

Two blocks are connected over a frictionless, massless pulley as shown in the figure. The mass of block A is $m_A$. The coefficient of kinetic friction between block A and the incline is $\mu_k$. The angle of the incline is $\theta$. Block A slides down the incline at a constant speed. The connecting rope has negligible mass.

Two blocks A and B, with masses $m_A$ and $m_B$, are placed together on a horizontal table as shown in Figure (a). The contact surface between them is smooth and inclined at an angle $\theta$ to the horizontal. The coefficient of static and kinetic friction between each block and the table is $\mu$. A horizontal force F is applied to block A.

Block A of weight $W_A$ rests on a horizontal table. It is connected by a string passing over a frictionless, massless pulley to a hanging block B of weight $W_B$. A third block C, of weight $W_C$, is placed on top of block A. The coefficient of static friction between block A and the table is $\mu_s$, and the coefficient of kinetic friction is $\mu_k$.