Answer:
The displacement of Sudhir is 0.781 km.
Explanation:
Given;
initial distance, d₁ = 0.4 km = 400 m, N60.0°W
final distance, d₂ = 0.5 km
Make a sketch of Sudhir motion to form a right angled triangle;
(Check image uploaded).
Apply cosine rule to determine d "displacement"
d² = 500² + 400² - (2 x 500 x 400 x cos 120)
d² = 410,000 - (400,000 x -0.5)
d² = 410,000 - (-200,000)
d² = 410,000 + 200,000
d² = 610,000
d = √610000
d = 781.03 m
d = 0.781 km
Therefore, the displacement of Sudhir is 0.781 km.