(1) The document discusses the Planck length and provides four expressions involving fundamental physical constants G, ħ, and c to determine its value.
(2) It describes a scenario where a man in a car wants to reach a point P in a field at a distance d from the highway. It asks for the distance RM that would result in the minimum time taken to reach P, given that the car's speed in the field is half of its highway speed.
(3) It provides the mass and acceleration of a body sliding down an inclined plane and asks for the external force required to take it back up the plane with the same acceleration, given the acceleration due to gravity.