Water Fountain ProblemWhen the water does not come out, it is at rest. As soon as the sensor is on, the water is coming out with a constant velocity. When the water bottle is moved away, the sensor is off, and now the water stop coming out. As it stops, it experiences a instant acceleration that decreases its velocity to zero.
|
Moving TankThe tank is moving in constant velocity. The people who took this picture (me) is sitting in a car behind this tank. The two vehicles have the same velocity: same speed and same direction. Therefore, the two vehicles is relatively at rest to each other, and they are moving according to the road and pedestrian.
|