$A$ ball of mass $m$ is thrown vertically upward. Another ball of mass $2m$ is thrown at an angle $\theta$ with the vertical. Both the balls stay in the air for the same period of time. The ratio of the maximum heights attained by the two balls respectively is $\frac{1}{x}$. The value of $x$ is $.....$

If a body moving in a circular path maintains a constant speed of $10\,ms^{-1},$ then which of the following correctly describes the relation between acceleration and radius?

$A$ particle is moving with a constant speed of $\sqrt{2} \, m/s$ on a circular path of radius $10 \, cm$. Find the magnitude of the average velocity when it has covered $\frac{3}{4}$ of the circular path.

$A$ stone of mass $0.25 \; kg$ is tied to the end of a string and is being whirled in a horizontal circle of radius $1.5 \; m$ with a speed of $40 \; rev./min$. If the speed of the stone is increased beyond the maximum permissible value and the string breaks suddenly,which of the following correctly describes the trajectory of the stone after the string breaks?
$(a)$ The stone moves radially outward.
$(b)$ The stone flies off tangentially from the instant the string breaks.
$(c)$ The stone flies off at an angle with the tangent whose magnitude depends on the speed of the particle.

Two bodies were thrown simultaneously from the origin: one straight up and the other at an angle of $60^{\circ}$ to the vertical. The initial velocity of each body is $10 \ m \ s^{-1}$. Neglecting air resistance, the distance between the two bodies after $t=2 \ s$ is (Use $g=10 \ m \ s^{-2}$):

Two stones are projected with the same speed but making different angles with the horizontal. Their ranges are equal. If the angle of projection of one is $\pi / 3$ and its maximum height is $h_1$,then the maximum height of the other will be: