Answer:
θr will increase.
Explanation:
We know that when light travel from one medium to another medium the relationship between refractive index and angle given as
na. sinθa = nb . sinθr

If na is increased (by using a different type of glass) but θa is kept the same then sinθr will also increase.
So answer is θr will increase.
Your variables would be varied temperature while your constants should be everything else (water, soil, proximity). Therefore, you can test for one variable (temperature difference) without muddling the results
Answer:
Displacement CO=2.15 Km
Average velocity = 1.99 Km/h
Explanation:
Given
Total time = 1.08 h
OA= 1.62 Km
AB=0.246 Km
BC=3.08 Km
θ=50.4°
CE=3.08 sin50.4° =2.37 Km
BE=3.08 cos50.4° =1.96 Km
CE=AB+OD
OD=CE-AB
OD=2.37-0.246
OD=2.124 Km
BE=CD+OA
CD=BE-OA
CD=1.96-1.62
CD=0.34 Km
Now CO


CO=2.15 Km
So the displacement CO=2.15 Km
Average velocity =Displacement/Time
Average velocity = 2.15/1.08 Km/h
Average velocity = 1.99 Km/h