1. The speed of light in a material is 1.93 x 10 8 m/s. What is the index of refraction of the material? 2. Light travels from water (index of refraction 1.33) into crown glass (index of refraction 1.52) at an angle of incidence of 42.0 degrees. Find the angle of refraction in the crown glass. (Ans: 35.8 degrees)
3. Determine the index of refraction of a liquid material if the angle of incidence in air is 40.0 degrees and the angle of refraction in the material is 25.9 degrees?

can someone solve and do working of these 3 questions please thanks alot.

The correct answer is  "c".  it is "c" because melting is an endothermic change, and endothermic get's energy from surroundings. 

Since you have not included the experiment situation and the data, of course, i can not give you specific details about it. but i can you with this question.1) i will assume that the motion is projectile (parabolic) motion.2) yes, the horizontal distance depends on the horizontal velocity as, naming vx the horizontal velocity and t the time, it is: x = vx × t3) now, observe that the flight time depends on the vertical velocity as, naming voy the initial vertical velocity, t the time and y the vertical distance before reaching the ground: y = yo + voy×t - gt² / 2.the higher the initial vertical velocity (voy) the longer the object will be flying and so t will be higher in the equation for the horizontal distance.that explains the relationship between the horizontal distance and the horizontal velocity.

The waves slow downn