Question

Two trains A and B moving with speed of 36km/hr and 72km/hr respectively in opposite direction.A man moving in train A with speed of 1.8km/hr opposite to direction of train.Find the velocity of man as seen from train B (in m/s).

Answer 1

GIVEN:-

• Two trains A and B moving with speed of 36km/hr and 72km/hr respectively in opposite direction.A man moving in train A with speed of 1.8km/hr opposite to direction of train.

TO FIND:-

• The velocity of man as seen from train B (in m/s).

SOLUTION:-

Vm relative to B = Vb - Va - Vm

$\implies \: 36 - 1.8 + 72 \\ \\ \implies \: 106.2kmph.$

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HOPE IT HELPS :)

Answer 2

Two trains A and B moving with speed of 36km/hr and 72km/hr respectively in opposite direction.A man moving in train A with speed of 1.8km/hr opposite to direction of train.

To find : The velocity of man as seen from the train B.

solution : speed of train A = 36 km/h = 36 × 5/18 = 10 m/s

speed of train B = 72 km/h = 72 × 5/18 = 20 m/s

speed of man moving in train A = 1.8 km/h = 1.8 × 5/18 = 0.5 m/s

let train A moving in positive direction of x - axis.

then, velocity of train A,$v_A$ = 10 i m/s

velocity of train B, $v_B$ = -20 i m/s

velocity of man moving in train A = - 0.5 i m/s

i.e., velocity of man with respect to train A , $v_{m,A}$= - 0.5 i m/s

now $v_{m,B}=v_{m,A}+v_{A,B}$

= -0.5i + {10i - (-20i)}

= -0.5 i + 30i

= 29.5 i m/s

Therefore the velocity of man as seen from the rain B is 29.5 m/s