A train is moving east at a speed of 5 ms -1. A bullet fired westwards with a velocity of 10 ms -1 crosses the train in 8 s. The length of the train is

Question

A train is moving east at a speed of 5 ms -1. A bullet fired westwards with a velocity of 10 ms -1 crosses the train in 8 s. The length of the train is (A) 120 m (B) 60 m (C) 30 m (D) 15 m

Tardigrade Admin · Accepted Answer

Take west as positive, then vB T=vB-vT=10-(-5)=15 ( m / s ) sB T=vB T. t=(15 ( m / s )) ⋅(8 s )=120 m

Q. A train is moving east at a speed of $5 m s^{- 1}$ . A bullet fired westwards with a velocity of $10 m s^{- 1}$ crosses the train in $8 s$ . The length of the train is

120 m

60 m

30 m

15 m

Take west as positive, then
$v_{BT} = v_{B} - v_{T} = 10 - (- 5) = 15 \frac{m}{s}$
$s_{BT} = v_{BT} . t = (15 \frac{m}{s}) \cdot (8 s) = 120 m$

Q. A train is moving east at a speed of 5ms−1. A bullet fired westwards with a velocity of 10ms−1 crosses the train in 8s. The length of the train is