A large cube of 25 kg is being accelerated across a frictionless horizontal surface by a horizontal force P. A small cube (4 kg) is in contact with the front surface of the large cube and will slide downwards unless P is sufficiently large. The coefficient of static friction between the cubes is 0.71.
a) Draw separate freebody diagrams for both the cubes.
b) What is the smallest magnitude of P in order to keep the small cube from sliding down?
The following posting helps with a problem involving static friction. Step by step solution provided.