When waves move into different materials, their speed changes. This can make it tricky to predict how the waves will act.

1. Change in Speed:

   • When waves go into a thicker material, they slow down.
   • But when they move into a thinner material, they speed up.

2. Refraction:

   • Because of this change in speed, waves start to bend.
   • This bending can make it hard to know where the waves will go next.

3. Snell's Law:

   • We can use something called Snell's Law to help understand refraction better. It explains how the angles of the waves change:
     $n_1 \sin(\theta_1) = n_2 \sin(\theta_2)$

To handle these challenges, we need to take careful measurements and do some calculations. Learning about how different materials bend waves can help us predict their behavior more easily.