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

Two balls $A$ and $B$ are thrown with the same velocity $u$ from the top of a tower. Ball $A$ is thrown vertically upwards and ball $B$ is thrown vertically downwards. If $t_A = 6 \ s$ and $t_B = 2 \ s$,then the velocity $u$ of each ball is ....... $m/s$.

$A$ body is thrown vertically upwards with a velocity of $35 \ m/s$ from the ground. The ratio of the speeds of the body at times $3 \ s$ and $4 \ s$ of its motion is (Acceleration due to gravity $= 10 \ m/s^2$)

$A$ body $A$ is projected upwards with a velocity of $98 \, m/s$. $A$ second body $B$ is projected upwards with the same initial velocity but after $4 \, s$. Both the bodies will meet after how many seconds (from the start of body $A$)?

The ratio of the displacements of a freely falling body during the second and fifth seconds of its motion is

$A$ body,thrown upwards with some velocity,reaches a maximum height of $50 \,m$. Another body with double the mass,thrown up with double the initial velocity,will reach a maximum height of............$m$.