A body projected vertically upwards with a velocity $u$ returns to the starting point in $4 \,seconds$. If $g = 10m/sec^2$, the value of $u$ is.........$m/sec$
A body projected vertically upwards with a velocity $u$ returns to the starting point in $4 \,seconds$. If $g = 10m/sec^2$, the value of $u$ is.........$m/sec$
$5$
$10$
$15$
$20$
A body projected vertically upwards with a velocity $u$ returns to the starting point in $4 \,seconds$. If $g = 10m/sec^2$, the value of $u$ is.........$m/sec$
Time of flight $T = \frac{{2u}}{g} = 4\;\sec \Rightarrow u = 20\;m/s$