Final answer:
A seismometer detects vertical and horizontal motion using sensors that measure the movement of the ground.
Step-by-step explanation:
A seismometer detects vertical and horizontal motion by using various types of sensors. The vertical motion is detected through a pendulum-like sensor called a vertical seismometer, which measures the up and down movement of the ground. The horizontal motion is detected using sensors called horizontal seismometers, which consist of mass suspended by springs that move relative to the ground.
When an earthquake or any other seismic activity occurs, the motion of the ground causes the sensors to move, which in turn generates electrical signals. These signals are then converted into digital data, which can be analyzed to determine the magnitude and duration of the seismic event.
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