A person is walking from the front of a train toward the back of a train at a constant velocity of 3 mph. The train is moving forward at a velocity of 20 mph. What is the velocity of the walking person relative to the land outside the train?

Explanation:

This is the Galilean transformation.

V' = V - U   where want to find V' in the primed frame of reference.

The primed frame is moving at speed U = -20 relative to the train.

V = -3 is the speed of the person in the frame of the train.

Then V' = -3 - (-20) = 17 mph relative to the land outside the train.

c. convergent boundary.

explanation:

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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