A bird is tossing (flying to and fro) between two cars moving towards

1.	A bird is tossing (flying to and fro) between two cars moving towards each other on a straight road. One car has a speed of 19 m/h while the other has the speed of 27 km/h. The bird starts moving from first car towards the other and is moving with the speed of 36 km/h and when the two cars were separated by 36 km. What is the total distance covered by the bird? What is the total displacement of the bird?
Answer» Let first car be A and second be B, Speed of car A, v_A = 18 km/h Speed of car B, v_B = 27 km/h Speed of bird, v = 36 km/h Relative speed of cars, v_AB = v_BA = v_A + v_B = 45 km/h Initial distance between cars, x = 36 km Time taken by cars to meet, t = \(\frac{x}{v_{AB}}=\frac{36}{45}\) km/h Distance covered by bird in the time, x' = v x t = 36 × 0.8 = 28.8 km Displacement of bird = distance covered by car A in 0.8 h on straight line (because bird starts from car A) ∴ x_A = v_A x t = 18 × 0.8 = 14.4 km Suppose man is at building A and wants to land on building B. Vertical speed of man, v_y = 0

A bird is tossing (flying to and fro) between two cars moving towards each other on a straight road. One car has a speed of 19 m/h while the other has the speed of 27 km/h. The bird starts moving from first car towards the other and is moving with the speed of 36 km/h and when the two cars were separated by 36 km. What is the total distance covered by the bird? What is the total displacement of the bird?

Answer»

Let first car be A and second be B,

Speed of car A, v_A = 18 km/h

Speed of car B, v_B = 27 km/h

Speed of bird, v = 36 km/h

Relative speed of cars,

v_AB = v_BA = v_A + v_B = 45 km/h

Initial distance between cars, x = 36 km

Time taken by cars to meet, t = \(\frac{x}{v_{AB}}=\frac{36}{45}\) km/h

Distance covered by bird in the time,

x' = v x t = 36 × 0.8 = 28.8 km

Displacement of bird = distance covered by car A in 0.8 h on straight line (because bird starts from car A)

∴ x_A = v_A x t = 18 × 0.8 = 14.4 km

Suppose man is at building A and wants to land on building B.

Vertical speed of man, v_y = 0