7. Friction, Inclines, Systems

A box of bananas weighing $40.0$ N rests on a horizontal surface. The coefficient of static friction between the box and the surface is $0.40$, and the coefficient of kinetic friction is $0.20$. If the monkey applies a horizontal force of $18.0$ N, what is the magnitude of the friction force and what is the box's acceleration?

Which of the following may result from an increase in kinetic friction between two surfaces?

Why does a moving object come to a stop when it moves across a surface with kinetic friction?

A 4.0-cm-diameter, 55 g ball is shot horizontally into a tank of 40°C honey. How long will it take for the horizontal speed to decrease to 10% of its initial value?

A 68-kg water skier is being accelerated by a ski boat on a flat ('glassy') lake. The coefficient of kinetic friction between the skier's skis and the water surface is μₖ = 0.25 (Fig. 5–59). What is the skier's acceleration if the rope pulling the skier behind the boat applies a horizontal tension force of magnitude F_T = 240N to the skier (θ = 0°)?

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In the context of kinetic friction, in which direction does the frictional force act relative to the motion of an object?

Why does an object that is sliding across carpet slow down?

Which of the following correctly identifies the two main types of friction encountered in physics?

When a block slides across a horizontal surface, how does kinetic friction affect its speed over time?

Which one of the following is an example of kinetic friction?

Which type of friction resists the movement of an object that is already in motion?

A car with mass $m$ is moving at constant velocity on a horizontal road. If the normal force between the tires and the road is $N$ and the frictional force opposing the motion is $F_k$, what is the coefficient of kinetic friction between the car’s tires and the road?

Which type of friction resists the motion of an object that is already moving along a surface?

While driving on a slippery highway, which action is most effective in reducing the risk of skidding due to kinetic friction between the tires and the road ($f\_k$)?