It is incorrect to say heavy objects sink in water because based on the density of the water it can actually cause the "heavy object" to float, out weighing it.
Answer:
The light bends away from the normal
Explanation:
We can solve the problem by using Snell's law:
where:
is the index of refraction of the first medium
is the index of refraction of the second medium
is the angle of incidence (angle between the incoming ray and the normal to the interface)
is the angle of refraction (angle between the outcoming ray and the normal to the interface)
We can rearrange the equation as
In this problem, light travels from an optically denser medium to an optically rarer medium, so
Therefore, the term 
is greater than 1, so
which means that the angle of refraction is greater than the angle of incidence, and so the light will bend away from the normal.
Answer: 0.0138 m^2 = 138 cm^2
Explanation:
The thermal expansion is the term use for the physical phenomena of dilation of the objects when they are exposed to changes in temperature.
The objects dilate when they are heated and contract when they are cooled.
The dilation is proportional to the change in temperatur.
For linear dilation, the proportionality constant is called linear dilation coefficient of the materials, it is named α and is measured in °C ^-1.
ΔL = α * Lo * ΔT, which means that the dilation (or contraction) is proportional to the product of the original length (Lo) and the change of temperature (ΔT).
There is also superficial dilation, for which the dilation is:
ΔA = β * Ao * ΔT, which means that the superficial dilation (or contraction) is proportional to the product of the original area (Ao) and the change of temperature (ΔT).
It is very interesting and important to solve problems that β = 2α, because regularly you will find the values of α for different materials and so, you just to multiply it times 2 to use β.
For this problem:
- Original area, Ao = area of the flat roof at - 10°C = 2.0m * 3.0m = 6.0 m^2.
- α for aluminum = 24 * 10^ -6 °C^-1.
- ΔT = 38°C - (-10°C) = 48°C
So, ΔA = 6.0m^2 * (2 * 24*10^-6 °C&-1) * 48°C = 0.0138 m^2
And that is the area that should stick out in summer to fit the structure during cold winter nights.
You can pass that number to cm^2 to grasp better the idea of this size:
0.0138 m^2 * (100 cm)^2 / m^2 = 138 cm^2
Answer:
True
Explanation:
Matter can be in the form of a particle or a wave. This is known as the dual nature of matter. This concept was proposed by Louis de Broglie and was named after him. This phenomenon has been observed for all the elementary particles.
The de Broglie wavelength is given by
Where
h = Planck's constant
p = Particles momentum
m = Mass of particle
v = Velocity of particle
