Question

4. A passenger in a train moving at 30 m/s passes a man standing on a station at
t = t ='0. Twenty seconds after the train passes him, the man on the platform
determines that a bird flying along the tracks in the same direction as the train is
800 m away.
(a) What are the coordinates of the bird as determined by the passenger?
(b) Five seconds after making the first coordinate measurement, the man on the
platform determines that the bird is 850 m away. Calculate velocity of the
bird as seen by the man on the platform and by the passenger of the train.​

Answer 1

Answer:

(a) $(800,0,0,20)$

(b) 10 m/s and 30 m/s

Explanation:

The speed of the train is 30 m/s

If we take the position of the passenger at the platform as reference coordinate position then the coordinates assign by him to the bird will be

(in terms of space and time both i.e. in $(x,y,z,t)$)

$(800,0,0,20)$

After 5 seconds, the bird has travelled = 850 - 800 = 50m

Th speed of the bird = Distance/Time

                                  = 50/5 = 10 m/s

Velocity of the bird as seen by the man on the platform = 10 m/s

Velocity of the bird as seen the passenger on the train = 30 - 10 = 20 m/s

Hope this helps.