while looking for a set of new tires for your car, you find an advertisement that offers two brands of tires, brand x and brand y, at the same price. Brand x has a coefficient of friction on dry pavement of .90 and on wet pavement of .15. Brand y has a coefficient of friction on dry pavement of .88 and on wet pavement of .45. If you live in an area with high levels of precipitation, which tires would give you better service? Explain.

A 5.95 kg block is sitting on a level floor.  A person is pulling on a rope attached to the block at a 34.84 degree angle above the horizontal (see figure). The force exerted by the person is 7.33 N.  What is the normal force acting on the block from its contact with the floor?

A factory needs to move packages from one level to another using a ramp. They want to choose a material that has a specific coefficient of friction with the packages that will be sliding down the ramp. What problem could occur if the coefficient of friction were too high?

A 1,480-N crate is being pushed across a level floor at a constant speed by a force of 350 N at an angle of 20.0° below the horizontal, as shown in the figure a below. F 20.0° / 20.0° a b (a) What is the coefficient of kinetic friction between the crate and the floor? (Enter your answer to at least three decimal places.) (b) If the 350-N force is instead pulling the block at an angle of 20.0° above the horizontal, as shown in the figure b, what will be the acceleration of the crate? Assume that the coefficient of friction is the same as that found in part (a). m/s²