The coefficients of friction between a block ofmass 1kg and a surface are s=0.54 andk=0.46. Assuming the only other force acting on theblock is that due to gravity, what is the force of friction (givemagnitude and direction) on the block: 1. if the block is at rest and the surface ishorizontal? 2. if the block is at rest and the surface is inclined at 17.5degrees? 3. if the block is moving downward and the surface is inclinedat 42.3 degrees? The coefficients of friction between a block ofmass 1kg and a surface are s=0.54 andk=0.46. Assuming the only other force acting on theblock is that due to gravity, what is the force of friction (givemagnitude and direction) on the block: 1. if the block is at rest and the surface ishorizontal? 2. if the block is at rest and the surface is inclined at 17.5degrees? 3. if the block is moving downward and the surface is inclinedat 42.3 degrees?
Explanation / Answer
The coefficients of friction between a block ofmass 1kg and a surface are s=0.54 andk=0.46. 1. if the block is at rest and the surface is horizontal =s * mg = 0.54 * 1 * 9.8 = 5.292 N 2. if the block is at rest and the surface is inclined at 17.5degrees = s * mg cos = 0.54* 1 * 9.8 * cos 17.5 = 5.04 N it act upward 3. if the block is moving downward and the surface is inclinedat 42.3 degrees is = k * mg cos 42.3 = 0.46*1*9.8* cos 42.3 = 3.334 N It act upward