Kinetic Friction — Prelims Questions

A block of mass $m = 2,\text{kg}$ is placed on a rough horizontal surface. The coefficient of kinetic friction between the block and the surface is $\mu_k = 0.3$. A horizontal force of $F = 10,\text{N}$ is applied to the block. Assuming the block is already in motion, what is the acceleration of the block? (Take $g = 10,\text{m/s}^2$)

A block slides down an inclined plane that makes an angle of $\theta = 30^circ$ with the horizontal. The coefficient of kinetic friction between the block and the plane is $\mu_k = 0.2$. What is the acceleration of the block down the incline? (Take $g = 10,\text{m/s}^2$, $\sin 30^circ = 0.5$, $\cos 30^circ = 0.866$)

A $4,\text{kg}$ block is pulled horizontally by a string with a tension of $20,\text{N}$. If the coefficient of kinetic friction is $0.4$, what is the acceleration of the block? (Take $g = 10,\text{m/s}^2$)

A block of mass $m$ is moving with an initial velocity $v_0$ on a horizontal surface. If the coefficient of kinetic friction is $\mu_k$, how far will the block slide before coming to rest?

Which of the following statements about kinetic friction is INCORRECT?

A $1,\text{kg}$ block is given an initial push and slides $5,\text{m}$ on a horizontal surface before coming to rest. If the initial speed was $5,\text{m/s}$, what is the coefficient of kinetic friction ($\mu_k$) between the block and the surface? (Take $g = 10,\text{m/s}^2$)