When light enters from water to glass what is the change in its velocity?

When a ray of light enters a glass slab,then

When light travels from air to water, which parameter does not change?

Light enters from air to glass having refractive index 1.50 what is speed of light in glass? Speed of light in vacuum is 3xx10^8 m s^-1 .

A particle moves in a circle of radius r with constant angular velocity omega . What is the change in velocity when the particle describe an angle of 90^@ ?

What is the effect when light enters from a rarer medium to a denser medium? Explain with diagram

Red light differes from blue light in its

A charged particle moving with a uniform velocity vecv enters a region where uniform electric and magnetic fields vecE and vecB are present. It passes through the region without any change in its velocity. What can we conclude about the relative direction of vecE , vecv and vecB?