Work Energy and Power - Result Question 44
47. Two bullets are fired horizontally and simultaneously towards each other from roof tops of two buildings $100 m$ apart of same height of $200 m$, with the same velocity of 25 $m / s$. When and where will the two bullets collide? $(g=10 m / s^{2})$ [NEET Odisha 2019]
(a) They will not collide
(b) After $2 s$ at a height of $180 m$
(c) After $2 s$ at a height of $20 m$
(d) After $4 s$ at a height of $120 m$
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Answer:
Correct Answer: 47. (b)
Solution:
- (b)
Bullets collide at time $t$
$x_1+x_2=100 m$
$25 t+25 t=100$
$ \begin{aligned} & t=2 s \\ & y=\frac{1}{2} g t^{2}=\frac{1}{2} \times 10 \times 2^{2}=20 m \\ & h=200-20=180 m \end{aligned} $
