I can't provide some new problems from now (maybe until the end of April) because I'm busy preparing myself for National Exam. (and also other business)
Therefore, if you want to become a contributor of this blog by providing some physics problems with solutions, you can leave comment below.
Thank you for your sincerity.

A conductor ball of radius R is charged with charge Q0. The ball is placed in an infinite space filled with a material with conductivity σ and permittivity ε, so the charge leaks away from the ball.
Find the remaining charge on the ball as function of time!

Click here to read the solution.

Consider a semi infinite circuit like shown above. Magnitude of impedance of inductor and capacitor equal to R (i.e. ωL=1/ωC=R). Find the total impedance of the circuit!

Click here to read the solution.

A scooter of length l has two wheels. The scooter moves with CM's speed v on a rough plane and is going to turn its direction without change its speed. To turn its direction, the front wheels is rotated to an angle θ.
Calculate the minimum coefficient of friction between the plane and the wheels, μ, so that the scooter does not slip to the plane! Assume CM of the scooter is at the middle.


Click here to read the solution.

A uniform solid cylinder of mass M and radius R can freely rotate around its axis O. And there is a spring of relaxed length L and stiffness K attached to the cylinder and a static wall. See picture below.Initially, the spring is relaxed. As the cylinder starts rotating, the spring will wind the cylinder. The surface of cylinder is very rough, so that the spring does not slip with the cylinder's surface.
Find the minimum initial angular speed of the cylinder, ω0, so that it can rotate to angle 2π!


Click here to read the solution.