Ahiker walks 4.5 km at an angle of 45° north of west. then the hiker walks 4.5 km south. what is the magnitude, angle, and direction of the hiker's total
displacement?

Magnitude of the hiker's total  displacement = 3.5 km

Angle and direction of the hiker's total  displacement = 22 degree south of west

Explanation:

The first Displacement in vector form is

= -4.5 cos 45i +4.5 sin 45j

= -3.182i + 3.182j

The second Displacement in vector form is  

= -4.5j

The total displacement is ,

= -3.182i + 3.182j - 4.5j

=-3.182i-1.318j

The magnitude of the displacement is,

s= 3.444

The direction is,

uranium fissions/breaks up giving out energy and neutrons

frequency or wavelenth of em radiation in a vacuum