Answer:
mb = 3.75 kg
Explanation:
System of forces in balance
ΣFx =0
ΣFy = 0
Forces acting on the box
T₁ : Tension in string 1 ,at angle of 50° with the horizontal on the left
T₂ = 40 N : Tension in string 2, at angle of 75° with the horizontal on the right.
Wb :Weightt of the box (vertical downward)
x-y T₁ and T₂ components
T₁x= T₁cos50°
T₁y= T₁sin50°
T₂x= 30*cos75° = 7.76 N
T₂y= 30*sin75° = 28.98 N
Calculation of the Wb
ΣFx = 0
T₂x-T₁x = 0
T₂x=T₁x
7.76 = T₁cos50°
T₁ = 7.76 /cos50° = 12.07 N
ΣFy = 0
T₂y+T₁y-Wb = 0
28.98 + 12.07(cos50°) = Wb
Wb = 36.74 N
Calculation of the mb ( mass of the box)
Wb = mb* g
g: acceleration due to gravity = 9.8 m/s²
mb = Wb/g
mb = 36.74 /9.8
mb = 3.75 kg
Answer:
Explanation:
Evolution is both a fact and a theory. Evolution is widely observable in laboratory and natural populations as they change over time. The fact that we need annual flu vaccines is one example of observable evolution. At the same time, evolutionary theory explains more than observations, as the succession on the fossil record. Hence, evolution is also the scientific theory that embodies biology, including all organisms and their characteristics. In this paper, we emphasize why evolution is the most important theory in biology. Evolution explains every biological detail, similar to how history explains many aspects of a current political situation. Only evolution explains the patterns observed in the fossil record. Examples include the succession in the fossil record; we cannot find the easily fossilized mammals before 300 million years ago; after the extinction of the dinosaurs, the fossil record indicates that mammals and birds radiated throughout the planet. Additionally, the fact that we are able to construct fairly consistent phylogenetic trees using distinct genetic markers in the genome is only explained by evolutionary theory. Finally, we show that the processes that drive evolution, both on short and long time scales, are observable facts.
According to the research, the correct option is a. The heat generated from the fission reaction is used to boil water, which rises and spins a turbine.
<h3>How is fision used to produce electricity?</h3>
In fusion, two atoms come together to form a larger one, releasing enormous amounts of energy in the process, this is used by generators to produce electricity.
As a result of nuclear fusion, large amounts of heat are generated that are used to produce pressurized steam, which allows mechanical energy to be obtained to start up electric power generators.
Therefore, we can conclude that according to the research, the correct option is a. The heat generated from the fission reaction is used to boil water, which rises and spins a turbine.
Learn more about fision reaction here: brainly.com/question/13207914
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Answer:
B) waves speed up
C) waves bend away from the normal
Explanation:
The index of refraction of a material is the ratio between the speed of light in a vacuum and the speed of light in that medium:
where
c is the speed of light in a vacuum
v is the speed of light in the medium
We can re-arrange this equation as:
So from this we already see that if the index of refraction is lower, the speed of light in the medium will be higher, so one correct option is
B) waves speed up
Moreover, when light enters a medium bends according to Snell's Law:
where
are the index of refraction of the 1st and 2nd medium
are the angles made by the incident ray and refracted ray with the normal to the interface
We can rewrite the equation as
So we see that if the index of refraction of the second medium is lower (
), then the ratio 
is larger than 1, so the angle of refraction is larger than the angle of incidence:
This means that the wave will bend away from the normal. So the other correct option is
C) waves bend away from the normal
Answer:
Acceleration is the change in velocity over the change in time = Δv/Δt. To do these problems, you need to find out how much the speed changed and over what period of time it changed.
Snail 1 changes from 4 cm/min to 7 cm/min in 3 minutes. Subtract the starting velocity (4 cm/min) from the ending velocity (7 cm/min) then divide by the time (3 min):
Snail 1 = (7 cm/min. - 4 cm/min)/(3 minutes) = ? (remember to put down the units)
Snail 2 changed from 7 cm/min. down to 1 cm/min. in 3 minutes
Snail 2 = (1 cm/min. - 7 cm/min.)/(3 min.) = ? (note that the acceleration is negative when you slow down)
I hope this helps you
