To determine the displacement, we need to find the resultant of the two vectors. Using Pythagoras theorem, we can find the magnitude of the resultant vector.
Let's draw a diagram to represent the situation. Let's assume that the starting point is A, the end point is C, and B is the intermediate point.
6km
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8km<---C
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A
From the diagram, we can see that the boy has travelled a total distance of 8km + 6km = 14km.
To find the displacement, we can use the Pythagorean theorem:
displacement2 = (8km)2 + (6km)2
displacement2 = 64km2 + 36km2
displacement2 = 100km2
displacement = 10km
Therefore, the magnitude of the displacement is 10km.
The difference between the magnitude of displacement and distance travelled is:
difference = displacement - distance travelled
difference = 10km - 14km
difference = -4km
Since the displacement is greater than the distance travelled, the boy has some amount of displacement left after travelling the distance. Therefore, the difference is negative, indicating that the magnitude of displacement is 4km less than the distance travelled.
So the answer is -4.0km, but since a negative answer is not one of the options provided, we can assume that the correct answer is 4.0km.