1) D
2) D.) Greater than 
Explanation:
1)
The phenomenon of total internal reflection occurs when a ray of light hitting the interface between two mediums is totally reflected back into the original medium, therefore no refraction into the second medium occurs.
This phenomenon occurs only if two conditions are satisfied:
- The index of refraction of the first medium is larger than the index of refraction of the 2nd medium
- The angle of incidence is greater than a certain angle called critical angle
In picture 1, we have 4 different diagrams. In the diagrams:
- The red arrow represents the incident ray
- The green arrow represents the refracted ray
- The blue arrow represents the reflected ray
Total internal reflection occurs when there is no refraction, therefore when there is no green arrow: this occurs only in figure D, so this is the correct option. (in figure C, there is a refracted ray but it is parallel to the interface: this condition occurs when the angle of incidence is exactly equal to the critical angle, however in this problem, the angle of incidence is greater than the critical angle, so the correct option is D)
2)
As we stated in problem 1), total internal reflection occurs when the angle of incidence is equal or greater than the critical angle. Therefore in this case, the angle of incidence must be
D.) Greater than
1Draw a quick sketch of the object.
2Draw an arrow showing every force acting on the object.
3<span>To calculate the net force, add any vectors acting on the same axis (x and y), making sure to pay attention to the directions.
Hope this helps :)
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Answer:
Distance= 4 miles
Time = 36.3 seconds
Explanation:
80 mph = 178.95 m/s
90 mph = 201.32 m/s
V = u +at
201.32= 0+a(4.5)
201.32/4.5= a
44.738 m/s² = a
Acceleration of the cop car
= 44.738 m/s²
Distance traveled at 4.5seconds
For the cop car
S= ut + ½at²
S= 0(4.5) + ½*44.738*4.5
S= 100.66 meters
Distance traveled at 4.5seconds
For the speeding car
4.5*178.95=805.275
The cop car will still cover 704.675 +x distance while the speeding car covers for their distance to be equal
X/178.95= (704.675+x)/201.32
X-0.89x= 626.37
0.11x= 626.37
X= 5694.3 meters
The time = 5694.3/178.95
Time =31.8 seconds
So the distance they meet
= 5694.3+805.275
= 6499.575 meters
= 4.0 miles
The Time = 4.5+31.8
Time = 36.3 seconds
Displacement and distance are two different things, distance is the total distance traveled, this would be easy in the case of the ant, that would simply be 15+25= 40cm.
But, displacement is the 'birds eye' distance between two points, in this question it can be worked out using Pythagoras. (there is a right angled triangle) imagine the base of this triangle is the east direction and north being the upright. then the displacement would be the largest side of the triangle, or the hypotenuse.
Pythagoras said that A^2 + B^2 = C^2
where C is the hypotenuse.
so 15^2 + 25^2 = C^2
C^2 =850
simply square root this to get C
sqrt(850) = 29.15 cm
29.15 cm displaced by the ant
D. A bimetallic strip bends so that the steel is on the outside curve.
