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During strenuous exercise, it is possible to exert forces to the joints that are easily ten times greater than the weight being supported. What is the maximum force of friction (in N) under such conditions? (The frictional forces in joints are relatively small in all circumstances except when the joints deteriorate, such as from injury or arthritis. Increased frictional forces can cause further damage and pain.) she exert 67.0 kg of her mass on that knee?

Two boxes (Box A = 9.7 kg and Box B = 5.4 kg) are connected by acord running over a pulley. The coefficient of kinetic friction betweenbox A and the table is 0.18. We ignore the mass of the cord and pulleyand any friction in the pulley, which means we can assume that a forceapplied to one end of the cord will have the same magnitude at theother end. We wish to find the tension of the cord while accelerating (inN), assuming the cord doesn’t stretch. As box B moves down, box Amoves to the right. Hint: Solve for the acceleration of the system first.

A 1.5 kg block resting ina rough flat surface is pulled by a string.  The string makes an angle of 20 degress with the horizontal.  The coefficient of static friction between the blodk and the surface is 0.35.  What is the maximum tension in the string to keep the block unmoved?

Calculate the maximum deceleration of a car that is heading down a 11.5° slope (one that makes an angle of 11.5° with the horizontal) under the following road conditions. You may assume that the weight of the car is evenly distributed on all four tires and that the static coefficient of friction is involved--that is, the tires are not allowed to slip during the deceleration. (a) on dry concrete m/s2 (b) on wet concrete m/s2 (c) on ice, assuming that ps = 0.100, the same as for shoes on ice m/s2 Additional Materials O Reading