Answer:
r = 78.95 m
Explanation:
given,
Person Walk in east, r₁ = 45 m
Then he walk, r₂= 39 m in the direction of 40◦ North of East.
writing the total displacement in x- direction
r₁ₓ = 45 m
r₂ₓ = 39 cos 40°
r₂ₓ = 29.87 m
total displacement in x-direction
rₓ = r₁ₓ + r₂ₓ
rₓ = 45 + 29.87
rₓ = 74.87 m
displacement in y-direction
r_{1y} = 0 m
r_{2y} = 39 sin 40°
r_{2y} = 25.07 m
total displacement in y- direction
r_y = 25.07 m
using Pythagoras theorem for the magnitude calculation
r = 78.95 m
The magnitude of total displacement is equal to 78.95 m.