If the coefficient of kinetic friction between the 40 kg crate and the floor is 0.680, what horizontal force must a worker exert to just start the motion of the crate?
If the worker maintains that force once the crate starts to move and the coefficient of kinetic friction between the surfaces is 0.500, what will happen to the crate?
If the worker applies force at an angle 60 degrees above the horizontal, what should be its value to just start the motion of the crate?
If the worker applies force at an angle 60 degrees below the horizontal, what should be its value to just start the motion of the crate?