Motion In One Dimension Question 2
Question 2 - 2024 (01 Feb Shift 2)
Train A is moving along two parallel rail tracks towards north with speed $72 \mathrm{~km} / \mathrm{h}$ and train B is moving towards south with speed $108 \mathrm{~km} / \mathrm{h}$. Velocity of train B with respect to A and velocity of ground with respect to $\mathrm{B}$ are $\left(\right.$ in $\left.\mathrm{ms}^{-1}\right)$ :
(1) -30 and 50
(2) -50 and -30
(3) -50 and 30
(4) 50 and -30
Show Answer
Answer: (3)
Solution:
B $\downarrow 30 \mathrm{~m} / \mathrm{s}$
$A^{\uparrow} 20 \mathrm{~m} / \mathrm{s}$
$V_{A}=20 \mathrm{~m} / \mathrm{s}$
$V_{B}=-30 \mathrm{~m} / \mathrm{s}$
Velocity of B w.r.t. A
$\mathrm{V}_{\mathrm{B} / \mathrm{A}}=-50 \mathrm{~m} / \mathrm{s}$
Velocity of ground w.r.t. B
$\mathrm{V}_{\mathrm{G} / \mathrm{B}}=30 \mathrm{~m} / \mathrm{s}$
