6. Intro to Forces (Dynamics)

The following forces are acting on a $250\mathrm{g}$ box on a horizontal surface. A downward force of gravity with magnitude $2.45\mathrm{N}$. An upward normal force with magnitude $2.45\mathrm{N}$. A rightward pull from a rope of $5.0\mathrm{N}$. A leftward kinetic friction force with magnitude $7.5\mathrm{N}$. At this instant, what is the magnitude of the acceleration of the box?

Tabletop shuffleboard is a popular pub game where players slide pucks across a tabletop trying to get them as close to the end of the table as possible, without falling off. Shuffleboard tables are typically covered in shuffleboard wax, which gives a very low coefficient of kinetic friction between the table and puck. Suppose that one particular table is 6.0 long m and has a coefficient of kinetic friction of 0.080. What speed should a player give to a puck on one end of the table so the puck just makes it to the far end?

A 40-kg crate is being lowered with a downward acceleration of 2.0 m/s² by means of a rope. What is the magnitude of the force exerted by the rope on the crate?