MCQ
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$5$
- B$10$
- C$15$
- ✓$20$
✓
Answer
Correct option: D.
$20$
d
(d)Time of flight $T = \frac{{2u}}{g} = 4\;\sec \Rightarrow u = 20\;m/s$
(d)Time of flight $T = \frac{{2u}}{g} = 4\;\sec \Rightarrow u = 20\;m/s$
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