Answer:
The block didn't slide due to balancing of gravitational force with friction force
Explanation:
When the block was given a flick the force provided an acceleration to it and it moved up the inclined plane. when the block reached top it was expected that it would slide back but it didn't this happened because of the frictional force acting on the bottom the block which was balancing the gravitational force component along the plane and this prevented sliding back of the block.
static friction was balancing mg*sin(theta)
fs = mg*sin(theta)
negative acceleration- deceleration
In this case, the air from the warm area will always start moving towards the colder areas because as the temperature in both lands should be equal. This is one of the laws of thermodynamics.