A bob is whirled in a horizontal circle by means of a string at an initial speed of $$10 \mathrm{~rpm}$$. If the tension in the string is quadrupled while keeping the radius constant, the new speed is:

Let $$\omega_1, \omega_2$$ and $$\omega_3$$ be the angular speed of the second hand, minute hand and hour hand of a smoothly running analog clock, respectively. If $$x_1, x_2$$ and $$x_3$$ are their respective angular distances in 1 minute then the factor which remains constant $$(k)$$ is

A ball is projected from point A with velocity $$20 \mathrm{~m} \mathrm{~s}^{-1}$$ at an angle $$60^{\circ}$$ to the horizontal direction. At the highest point $$\mathrm{B}$$ of the path (as shown in figure), the velocity $$\mathrm{v} \mathrm{m} \mathrm{s}^{-1}$$ of the ball will be:

A particle is executing uniform circular motion with velocity $$\vec{v}$$ and acceleration $$\vec{a}$$. Which of the following is true?