A warehouse robot moves along a straight aisle. Its position is measured relative to its starting point. Positions to the east are positive and positions to the west are negative.
| Position record | Position of robot |
|---|---|
| Start | 0 m |
| After first movement | +240 m |
| After second movement | +150 m |
| After third movement | -60 m |
After the third movement, the robot moves a further 100 m east.
Calculate the total distance travelled by the robot.
Calculate the displacement of the robot from its starting point after its further movement.
Explain why the distance travelled and the displacement have different values for this journey.