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help A car is traveling at 49.0 mi/h on a horizontal highway. If the coefficient

ID: 2116525 • Letter: H

Question

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A car is traveling at 49.0 mi/h on a horizontal highway. If the coefficient of static friction between road and tires on a rainy day is 0.099, what is the minimum distance in which the car will stop? m What is the stopping distance when the surface is dry and mu s = 0.597? A 26.0-kg block is initially at rest on a horizontal surface. A horizontal force of 79.0 N is required to set the block in motion, after which a horizontal force of 58.0 N is required to keep the block moving with constant speed, Find the coefficient of static friction between the block and the surface. Find the coefficient of kinetic friction between the block and the surface.

Explanation / Answer

Change in Kinetic ENERGY = Work Done by Friction


0.5*m*21.905^2 = 0.099*m*9.8*s


s = 247.283 m


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Change in Kinetic ENERGY = Work Done by Friction


0.5*m*21.905^2 = 0.597*m*9.8*s


s = 41 m


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Force required = usmg


us = Coeff. of Static friction = (79)/(26*9.8)


= 0.31



Force required = ukmg


uk = Coeff. of Kinetic friction = (58)/(26*9.8)


= 0.227