A train is moving 50km/h east. A person is walking 5 km/h west on the train. How fast is the person on the train going relative to an observer on the earth?
45 km/h east
Because
person's velocity with respect top land =
Person's velocity with respect to train + train's velocity with rsepect to land.
= -5 + 50
The minus sign of the first term is there because the person is walking opposite to the train's direction.
To determine the speed of the person on the train relative to an observer on the Earth, you need to consider their individual velocities and the direction in which they are moving.
The train is moving at a speed of 50 km/h to the east (positive direction), and the person is walking at a speed of 5 km/h to the west (negative direction) on the train.
To find the relative speed, you need to subtract the velocity of the person from the velocity of the train. In this case, since the person is moving in the opposite direction from the train, you subtract their velocities:
Relative speed = Velocity of the train - Velocity of the person
Relative speed = 50 km/h (east) - 5 km/h (west)
By considering direction, the relative speed is calculated as follows:
Relative speed = 50 km/h + 5 km/h
Thus, the relative speed of the person on the train, as observed by someone on the Earth, is 55 km/h to the east.