A piece of ice slides down a rough inclined plane at $$45^{\circ}$$ inclination in twice the time that it takes to slide down an identical but frictionless inclined plane. What is the coefficient of friction between ice and incline?

A body of mass 5 kg is suspended by a spring balance on an inclined plane as shown in figure.

So, force applied on spring balance is

In the figure, blocks A and B of masses 2m and m are connected with a string and system is hanged vertically with the help of a spring. Spring has negligible mass. Find out magnitude of acceleration of masses 2m and m just after the instant when the string is cut

In the figure, mass of a ball is $$\frac{9}{5}$$ times mass of the rod. Length of rod is $$1 \mathrm{~m}$$. The level of ball is same as rod level. Find out time taken by the ball to reach at upper end of rod.