Which of the following represents the velocity-time graph for a ball thrown vertically upwards (neglecting air resistance)?

The acceleration of a vertically projected body at its highest reaching position is

$A$ ball is projected upwards from a height $h$ above the surface of the earth with velocity $v$. The time at which the ball strikes the ground is

$A$ ball is thrown vertically upward with an initial velocity of $150\,m/s$. The ratio of velocity after $3\,s$ and $5\,s$ is $\frac{x+1}{x}$. The value of $x$ is $...........$ Take $g=10\,m/s^2$.

Two spherical balls having equal masses with a radius of $5 \, \text{cm}$ each are thrown upwards along the same vertical direction at an interval of $3 \, \text{s}$ with the same initial velocity of $35 \, \text{m/s}$. These balls collide at a height of $\ldots \ldots \ldots \, \text{m}$. (Take $g = 10 \, \text{m/s}^2$)

Two bodies are thrown simultaneously from a tower with the same initial velocity $v_0$: one vertically upwards,the other vertically downwards. The distance between the two bodies after time $t$ is