An object is attached to a cable to a crate. Assume a pulley and ignore friction and mass of pulley. The coefficients of friction between the crate and the rooftop are 0.2 and 0.3.
At what mass ratio between the object and the crate will the crate begin to slide

Now assume that the object is 90 kg and the crate is 100 kg. What is the acceleration of the crate?

What is the magnitude of The objects acceleration?