posted by eric .
The drawing shows a large cube (mass = 48 kg) being accelerated across a horizontal frictionless surface by a horizontal force . A small cube (mass = 2.1 kg) is in contact with the front surface of the large cube and will slide downward unless is sufficiently large. The coefficient of static friction between the cubes is 0.71. What is the smallest magnitude that can have in order to keep the small cube from sliding downward?