Answer:
10.791 kJ
Explanation:
Given that,
Mass of the skier, m = 58 kg
Initial position, h₁ = 24 m
Final position, h₂ = 19 m
We need to find the kinetic energy do they have at the top of the second hill.
Using the conservation of energy for both positions.
[tex]v_1=\sqrt{2gh_1} \\\\=\sqrt{2\times 9.8\times 24} \\\\=21.68\ m/s[/tex]
And
[tex]v_2=\sqrt{2gh_2} \\\\=\sqrt{2\times 9.8\times 19} \\\\=19.29\ m/s[/tex]
Kinetic energy :
[tex]K=\dfrac{1}{2}mv_2^2\\\\K=\dfrac{1}{2}\times 58\times 19.29^2\\\\=10791.01 J\\\\=10.791\ kJ[/tex]
So, the kinetic energy they have at the top of the second hill is 10.791 kJ.
A solar cell that transforms 300 J of light energy into 45 J of electrical energy and 255 J of wasted energy. whats the efficiency
Answer:
15%
Explanation:
Step one:
Given data
Energy source= 300J
Useful energy = 45J
Waste energy = 255J
Required
The efficiency of the solar system
Step two:
The efficiency is computed by factoring only the useful work and the energy source
Efficiency= 45/300*100
Efficiency= 0.15*100
Efficiency= 15%
You shine light on a material. 50% of it is reflected by the surface. A further 10% of the original light is absorbed by the material. What is the transmittance of the material?
Answer: T = 40%
Explanation: The definition of Transmittance is a part of the incident light that passes through a surface or material moves through the other side of the surface. It is represented as T and is defined as the ratio of the intensity of incident light to the intensity of light that passes through the surface:
[tex]T=\frac{I}{I_{0}}[/tex]
where
I is intensity that passes through
I₀ is incident intensity
When you shine a light on a material and 50% of it is reflected, the remaining 50% will try to pass through. However, 10% is absorbed leaving 40% of the light to move through the other side of the surface.
So, Transmittance of this surface is 40%.
A ray diagram is shown.
Answer:
Angle of Refraction ?
Explanation:
My decided answer on this question
What are the social consequences of sustainable use of land?
Major land–use changes have occurred in the United States during the past 25 years. The total area of cropland, pastureland and rangeland decreased by 76 million acres in the lower 48 states from 1982 to 2003, while the total area of developed land increased by 36 million acres or 48%. What are the potential economic, social and environmental impacts of land use changes? How does land use change affect agriculture and rural communities? What are the important economic and environmental implications for commodity production and trade, water and soil conservation, open space preservation, and other policy issues? This article addresses some of these issues and their policy implications.
A graph that plots the temperature of a star against its brightness.
A. Electromagnetic Radiation
B. Especstroscopy
C. HertzPrung Russel Diagram
Answer:
C. HertzPrung Russel Diagram
Explanation:
The Hertzsprung–Russell diagram, or H–R diagram, is a plot of stellar luminosity against surface temperature. Most stars lie on the main sequence, which extends diagonally across the H–R diagram from high temperature and high luminosity to low temperature and low luminosity.
a ball is thrown vertically upwards from the ground. The ball rises and falls back to the ground. Describe the changes in the mechanical energy of the ball as it rises.
Answer:
as the ball is thrown, the enegry rises up, when it falls, the ball relseases all energy
Explanation:
How do you score a goal in team handball ?
Answer:a goal is scored by throwing the ball into the goal post and is confirmed by deciding that’s if the ball has hit the tape mark or not
Explanation:
Based on details in The Riddle of the Rosetta Stone, which statement best describes Jean-Baptiste Fourier's influence on Jean-François Champollion?
Answer:
hello your question is incomplete below is the missing part of the complete question
which statement best describes Jean-Baptiste Fourier’s influence on Jean-François Champollion? Fourier shared his research about mathematics with Champollion, which aided him in his research. Fourier was the first to introduce Champollion to the hieroglyphs on the Rosetta Stone, which fascinated him. Fourier shared his findings about the Rosetta Stone with Champollion, which helped him in his research. Fourier was the first to introduce Champollion to a variety of languages, which prompted his love of languages.
answer : Fourier was the first to introduce Champollion to a variety of languages, which prompted his love of languages.
Explanation:
Jean-Baptiste Fourier's influence on Jean-Francois Champollion is that Fourier was the first to introduce Champollion to a variety of languages, which prompted his love of languages. also Fourier was a mathematician who pleaded on the behalf of Champollion when he was about to be adopted into the military.
50 POINTS !!!
What happens to ice when in water?
identfy the parts of he atom that are labeied in the
dagram
Label A:
Label B
NEED THE ANSWE ASAP!
Answer :
Label A - nucleus.
Label B- electron cloud.
Explanation :
An atom is the smallest unit of a matter that consist of three subatomic particles which are electrons, protons and neutrons.
The protons and the neutrons are located inside the nucleus or the center of the nucleus where the mass of the an atom is concentrated.
The electrons are located around the nucleus.
The protons are positively charged, the electrons are negatively charged and the neutrons are neutral that means it has no charge.
In the picture, label A shows the nucleus.
Electrons has the ability to revolve around the nucleus in a fixed circular orbit. Electron cloud represents the spreading of the electrons energy.
In the picture, label B shows the electron cloud.
Hence, the label A - nucleus and label B- electron cloud.
A tractor trailer truck traveling at a speed of 105 feet/second skids to a stop in 12 seconds. Determine the skidding distance of the truck.
Please help.
Answer:
1260ft
Explanation:
Given parameters:
Speed = 105ft/s
Time = 12s
Unknown:
Skidding distance of the truck = ?
Solution:
To solve this problem:
Distance = speed x time
Now insert the parameters and solve;
Distance = 105 x 12 = 1260ft
What will be the average velocity of a body falling in free fall on Earth for 3 s?
Answer:
29.4m/s
Explanation:
Given parameters:
Time = 3s
Unknown:
Average velocity = ?
Solution:
To solve this problem, we use the expression below:
v = u + gt
v is the average velocity
u is the initial velocity = 0m/s
g is the acceleration due to gravity = 9.8m/s²
t is the time
So;
v = 0 + (9.8 x 3) = 29.4m/s
Distinguishing between Speed and Velocity.
Answer:
Speed: Distance per time, 400 km/h, and a scalar quantity.
Velocity: Displacement per time, 20 m/s south, and a vector quantity.
Explanation:
Hope this helps! Please mark as brainliest.
Thanks!
Dexter Eius is running through the cafeteria when he slips on some mashed potatoes and falls to the floor. (Let that be a lesson for Dexter.) Dexter lands in a puddle of milk and skids to a stop with an acceleration of -4.8 m/s/s. Dexter weighs 780 Newtons. Determine the coefficient of friction between Dexter and the milky floor.
Answer:
μ = 0.49
Explanation:
For this exercise we can use Newton's second law
Y Axis
N - W = 0
N = W = mg
X axis
-fr = ma
the equation for the friction force is
fr = μ N
we substitute
-μ m g = ma
μ = -a / g
we calculate
μ = 4.8 / 9.8
μ = 0.49
A seismic wave is energy released as the result of rock movement along a fault.
T/F
Answer:
TRUE
Explanation:
Which of the following statements best describes the relationship between the environment and the collective health of the world? A. The environment does not affect our health. B. When the environment is damaged, our health improves. C. What is good for the environment is good for our health. D. Our collective health is not related to the health of the environment. Please select the best answer from the choices provided. A B C D Mark this and return
Answer:
its C
Explanation:
The statement that describes the relationship between the environment and the collective health of the world is; "what is good for the environment is good for our health."
Humans must maintain a very good interaction with their environment because the interaction between man and his environment is very necessary for healthy living.
Man depends on water, air etc to sustain life. These are part of the natural environment, when these are polluted due to neglect of the environment, human health is adversely affected.
Learn more: https://brainly.com/question/4593618
Can y’all help please
Answer:
advantages of using renewable energy resource
it is safer and cleaner
it does not produces green house gas and has 0 carbon emission
for producing electricity we use solar and wind power that does not harm the environment
advantages of using non renewable energy resource
they are abundant
they are affordable
easy to use
they are easily accessible and compatible
easy to store
6. Which phase of matter has a definite volume and shape.
a. solid
b. liquid
c. gas
d.plasma
Answer:
solids
Explanation:
beacause if you take an ice cube does it change its shape no and if it has a definite shape it is sure to have a definite volume
The person with the greatest ___ hits earth first
A. Volume
B. Mass
C. Density
D. Weight
The person with the greatest density will hit the earth first.
What is Density?This is regarded as the mass per unit volume of a substance.
Density = mass/ volume
In objects with different densities, the drag and buoyancy forces will be the
same. They will however have different gravitational force in which the
denser object has more compared to lighter ones.
Read more about Density here https://brainly.com/question/1354972
Speed – time graph of uniform motion is horizontal straight line.
Select one:
a. TRUE
b. FALSE
Which type of electromagnetic waves would the best to use in an object designed to cook food?
А. gamma waves
B. visible waves
C. infrared waves
D. microwaves
Answer:
C. infrared waves
Explanation:
Microwaves are the electromagnetic waves which would the best to use in an object designed to cook food. Thus, the correct option is D.
What are Microwaves?Microwave is a form of electromagnetic radiation with the wavelengths ranging from about one meter to about one millimeter which is corresponding to the frequencies in the range between 300 MHz and 300 GHz, respectively.
Microwaves are used for cooking food faster than the conventional ovens and would not make a mess in the process. This reheats food instantly quickly. It is helpful for the health conscious people. Microwaves also ensure that a person will never burn the food again. Microwaves are also very economical and energy efficient.
Therefore, the correct option is D.
Learn more about Microwaves here:
https://brainly.com/question/15708046
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Glider A of mass 0.355 kg moves along a frictionless air track with a velocity of 0.095 m/s. It collides with glider B of mass 0.710 kg moving in the same direction at a speed of 0.045 m/s. After the collision, glider A continues in the same direction with a velocity of 0.035 m/s. What is the velocity of glider B after the collision?
Answer:
vB' = 0.075[m/s]
Explanation:
We can solve this problem using the principle of linear momentum conservation, which tells us that momentum is preserved before and after the collision.
Now we have to come up with an equation that involves both bodies, before and after the collision. To the left of the equal sign are taken the bodies before the collision and to the right after the collision.
[tex](m_{A}*v_{A})+(m_{B}*v_{B})=(m_{A}*v_{A'})+(m_{B}*v_{B'})[/tex]
where:
mA = 0.355 [kg]
vA = 0.095 [m/s] before the collision
mB = 0.710 [kg]
vB = 0.045 [m/s] before the collision
vA' = 0.035 [m/s] after the collision
vB' [m/s] after the collison.
The signs in the equation remain positive since before and after the collision, both bodies continue to move in the same direction.
[tex](0.355*0.095)+(0.710*0.045)=(0.355*0.035)+(0.710*v_{B'})\\v_{B'}=0.075[m/s][/tex]
What is the momentum of a 120 pound bicyclist that is traveling at 25 mph?
9th grade science here, please help will mark brainliest
Answer:
positive. hope this helped
5. How much power is dissipated when 0.2 ampere of current flows through a 100-ohm resistor ?
Answer:
P=I*I*R
Where P is power
I is current
R is Resistance
P=2*2*100
P=400W
Explanation:
Power is the rate of doing work.
From the Ohm’s law V=IR
Power=I*I*R
List various ways through which AIDS spreads
please its aurgent fast
Answer:
Blood, semen, bodily fluids, breast milk
Explanation:
Explanation:
Through.....
1) blood
2) breast feeding
3) semen
4) unprotected sex etc
consequences and application of heat
Answer:
Prolonged exposure to extreme heat can cause heat exhaustion, heat cramps, heat stroke, and death, as well as exacerbate preexisting chronic conditions, such as various respiratory, cerebral, and cardiovascular diseases.
What is everything in our physical environment made of? *
A matter
B solids
C gases
Answer: matter
Explanation:
A person walks 2.00 m east, then turns and goes 4.00 m west, then turns and goes back 1.00 m east.
Answer:
i got -1.00
Explanation:
Answer:
he is 1.0 west in the end.
Explanation:
think of it like a number line and you are starting on 0.
2.0m east is like 2 steps to the left (-2). Then you go back to the right (west) 4 steps (ending up at 2.0 meters). then you take one step back in the other direction where you are now at 1.0m on the right or west of 0.
Two objects are shown below. One is neutral and the other is negative. What do you predict would happen?
Answer:
The body becomes a positive charged body.
Explanation:
Given that two objects are shown below. One is neutral and the other is negative. What do you predict would happen?
According to the law of static electricity, like charges repel each other while unlike charges attract each other.
Since one of the object is neutral and the other one is negative, there will neither attraction nor repulsion between them.
Also, according to Electrostatic induction, the neural body can be charged and becomes positive.
The negative body will attract all the positive charges to its side, and repel all the negative charges to the other side. If the body is touched at the other end, the whole negative charges will be earthed and the body will become a positive body.