2. Block A weighs 100N. The coefficient of static friction between the block and the surface upon which it sits is 0.30. The weight w is 20N and the system is in equilibrium. A) Find the frictional force exerted on Block A. and B) find the maximum weight w for which the system will remain in equilibrium.
3. A safe weighing 2000N is to be lowered at constant speed down a skids 4m long from a truck 2m above the ground.
a) if the coefficient of sliding friction between the safe and the skids is 0.30, will the safe need to be pulled down or held back ?
b) how great a parallel force will be needed ?