Laws of Motion ...

A rigid ball of mass m strikes a rigid wall at $$60^0$$ and gets reflected without loss of speed as shown in the figure. The value of impulse imparted by the wall on the ball will be:

A house is on built on the top of a hill with $$45^0$$ slope. Due to the sliding of material and sand from top to the bottom of hill, the slope angle has been reduced.
If the coefficient of static friction between sand particles is 0.75, what is the final angle attained by hill? ($$ tan^{-1}0.75 = 37^0$$)

A man revolves a stone of mass m tied to the end of a string in a vertical circle of radius R, The net force at the lowest and height points of the circle directed vertical downwards are 
Here $$T_1, T_2$$ and  $$v_1, v_2$$ denote the tension in the string and the speed of the stone at the lowest and highest points, respectively.

For the conditions of the equilibrium of the body, i.e. the rigid body only the external forces defines the equilibrium. Because the internal forces cancels out so not to be considered.

Two wires $$AC$$ and $$BC$$ are tied at $$C$$ of a small sphere of mass $$5\ kg$$, which revolves at a constant speed $$v$$ in the horizontal plane with the speed $$v$$ of radius $$1.6\ m$$. Find the minimum value of $$v$$.

Which of the following is correct?

A particle of mass 1 kg is suspended by means of a string of length L=2 m. The string makes $$6/\pi$$ rps around a vertical axis through the fixed end. The tension in the string is

A mass attached to a string that is itself attached to the ceiling swings back and forth. If the bob is observed to be moving upward at a given instance, as shown to the right, which arrow best depicts the direction of the net force acting on the bob at that instant

Two blocks of same mass ($$4$$kg) are placed according to diagram. Initial velocities of bodies are $$4$$ m/s and $$2$$ m/s and the string is taut. Find the impulse on $$4$$ kg when the string again becomes taut.

Momentum of an object changes from $$5\ kg\ m/s$$ to $$15\ kg\ m/s$$ in $$2$$ seconds. What is the force applied on the object?