The coefficient of static friction is 0.65 between the two blocks. The coefficient of kinetic friction between the lower block and the floor is 0.20. Force causes both blocks to cross a distance of 6.5 m, starting from rest. What is the least amount of time in which this motion can be completed without the top block sliding on the lower block?
2006-10-30 14:09:45 · 1 answers · asked by Anonymous in Science & Mathematics ➔ Physics
The maximum friction force that the lower block can exert on the upper block is equal to 0.65mg, where m is the mass of the upper block and g is the acceleration due to gravity. This force would accelerate the block at 0.65g, and this is the maximum acceleration that the upper block can experience. It will happen when the lower block is itself accelerating at 0.65g. If the lower block accelerated faster, it would be unable to supply enough force to keep the upper block from falling off. So, rearranging the formula x = 0.5*a*t^2 into t = sqrt(2x/a), and using the distance you were given for x and the acceleration of 0.65g for a, calculate the time.
2006-11-01 08:29:37 · answer #1 · answered by DavidK93 7 · 0⤊ 0⤋