Reflection<span> is bouncing off a barrier or interface. </span>Refraction<span> is bending of light's path at the interface between two media. All angles are to be measured from the normal to the surface. The incident angle and the reflected angle are equal. The refracted angle may be larger or smaller than the incident angle.</span>
<span>The </span>index of refraction, n, is a ratio that compares the speed of light in a vacuum to the speed of light in another medium.
n = c/v where c = speed of light in a vacuum = 3x108<span> m/s</span>
The speed of light in all other media is less than in a vacuum. Therefore, n is always larger than one. It may be thought of as the measure of the slowness of light in a medium: the slower light travels in medium, the larger n will be for that medium. Since n divides speed by speed it has no units.
The frequency of light does not change as it enters a different medium, but its wavelength does. Since
v = fL where f = frequency and L = wavelength
then
v1/v2<span> = L</span>1/L<span>2
</span>EXAMPLE
1.
a. What is the speed of light in water, if water's index of refraction is 1.33?
b. If the wavelength of a ray of light in a vacuum is 1x10-6 m, what is its wavelength in water?
ANSWER
1.
a. n = c/v
1.33 = (3 X 108 m/s)/v
v = 2.26x108 m/s
b. v1/v2 = L1/L2
(2.26x108 m/s)/(3x108 m/s) = L1/(1x10-6 m)
L1 = 7.52x10-7 m
Extinction is a natural part of life on Earth. Over the history of the planet most of the species that ever existed, evolved and then gradually went extinct. Species go extinct because of natural shifts in the environment that take place over long periods of time, such as ice ages.
Today, species are going extinct at an accelerated and dangerous rate, because of non-natural environmental changes caused by human activities. Some of the activities have direct effects on species and ecosystems, such as:
Habitat loss/ degradation
Over exploitation (such as overfishing)
Spread of Non-native Species/ Diseases
Some human activities have indirect but wide-reaching effects on biodiversity, including:
Climate change
Pollution
All of these threats have put a serious strain on the diversity of species on Earth. According to the International Union for Conservation of Nature (IUCN), globally about one third of all known species are threatened with extinction. That includes 29% of all amphibians, 21% of all mammals and 12% of all birds. If we do not stop the threats to biodiversity, we could be facing another mass extinction with dire consequences to the environment and human health and livelihood.
Answer
The moveable parts of the pop up book are of often cut out by hand and are folded and glued by hand upon the printed pages. The cover is glued or sewn to the lining. Front and backs are often made up from board, which is just a heavier gauge paper than is used for the pages.
Explanation
Hope that this helps you and have a great day:)
Heating the gas in an air balloon makes the balloon rise<span> because the </span>gas<span> in the</span>balloon<span> becomes lighter than natural </span>air<span>. The </span>heated gas<span> has less mass per unit of volume than that of the cool </span>air<span> surrounding the </span>balloon<span>. Hope this answers the question.</span>
We have 2 conditions of balance. First of all, the total forces have to have a net sum of 0 since the bridge is balancing. Hence, if we denote by F1 the force of the first pole, F2 the power of the second pole (the one closer to the car), W the weight of the bridge and w the weight of the car, we have that W+w=F1+F2=4.196*10^5 N.
We also have that it does not rotate. Hence, taking as origin of our frame of reference the car, we have that 5*F2+4*W=9*F2 by calculating the distances from our point of reference. Thus yields 5F2+8*10^5=9F2. When we solve the system of equations that is created above (best way here is by substitution), we get that F1=2.07*10^5 N while F2=2.126*10^5 N . Each pole takes up around half the weight but due to the car the pole closer to it has more weight to bear; nevertheless the car does not weigh a lot so the difference is small.
