We use a plane mirror to see our face, Why?

Plane mirror causes regular reflection of light. When a parallel beam of light is incident on a plane mirror it is reflected back parallely. Due to this property a plane mirror is used to see our image and not a rough surface

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west

the rearrangement of particles in a physical change. hope this