What happens to the speed of light as it enters a different medium

If the light enters one medium to another medium then the speed of light gets change.

Explanation:

When the light enters from rare medium to denser medium then the light gets bend towards normal.

When the light enters from denser medium to rarer medium then the light gets bend away from normal.

If the light enters one medium to another medium then the speed of light gets change and the direction of light also gets change. Only the frequency of the light remains during this phenomenon. The wavelength of the light gets decreased.

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg