Uses of concave and convex mirror
hello?

Used for reflecting angles, used by dentists

Explanation:

c)as speed changes, wavelength and frequency change.

everything changes!

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