Answer:
Because radiation does not require material medium for its propagation.
Explanation:
Radiation is one of the types of modes of heat transfer that takes place majorly in gases. Heat energy can be transferred through gases by radiation without heating up the intervening medium. Even, if the available molecules of gases are evacuated, the heat energy would propagate.
Thus, student's hands were not heated by convection since convection is a mode where material medium is required for propagation of heat energy.
Her hands are not heated by convection because radiation does not require material medium for its propagation.
Radiation
It is one of the types of modes of heat transfer that takes place majorly in gases. Heat energy can be transferred through gases by radiation without heating up the intervening medium. Even, if the available molecules of gases are evacuated, the heat energy would propagate.The sun's light and heat cannot reach us by conduction or convection because space is almost completely empty. There is nothing to transfer the energy from the sun to the earth.Thus, student's hands were not heated by convection since convection is a mode where material medium is required for propagation of heat energy.
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A projectile is launched with an initial velocity of (40 m/s), at an angle of (30°) above
horizontal. What is the maximum height (ymax) reached by the projectile?
(Use g=10 m/s2).
Answer:
330.5 m
Explanation:
In this case, the object is launched horizontally at 30° with an initial velocity of 40 m/s .
The maximum height will be calculated as;
[tex]h=\frac{v^2_isin^2\alpha }{2g}[/tex]
where ∝ is the angle of launch = 30°
vi= initial launch velocity = 40 m/s
g= 10 m/s²
h= 40²*sin²40° / 2*10
h={1600*0.4132 }/ 20
h= 661.1/2 = 330.5 m
50 POINTS!!!!!!!!!!
Eating peanut butter on whole wheat toast causes the blood glucose level to increase. When this happens, glucose from the blood is then absorbed by the muscles and liver. Which feedback mechanism is used to regulate blood glucose?
OA) a positive feedback loop because the blood glucose level was returned to the set point, not amplified
OB) a negative feedback loop because the blood glucose level was returned to the set point, not amplified
OC)a negative feedback loop because the blood glucose level was amplified, not returned
OD) to the set point a positive feedback loop because the blood glucose level was amplified, not returned to the set point
Answer: if i was doing this i would have chosen C
Explanation:
An object has a tangential velocity of 23 m/s as it moves around a circular track with a
radius of 20 meters. What is the object's acceleration
Answer:
26.5m/s²
Explanation:
Given parameters:
Tangential velocity of the object = 23m/s
Radius of track = 20m
Unknown:
Acceleration = ?
Solution:
The acceleration of the body is its centripetal acceleration. It is given by;
a = [tex]\frac{v^{2} }{r}[/tex]
v is the tangential velocity
r is the
a = [tex]\frac{23^{2} }{20}[/tex] = 26.5m/s²
Why Don't Birds Get Electrocuted When They Land on Electric Wires?
Answer:
There is a thick layer of rubber coating on the wires.
Explanation:
This isn't just the case with birds, your headphones, if you notice closely have a layer of rubber coating as well, to protect you from accidentally touching the wires inside and hurting yourself.
5. A pendulum is 0.25 m long. What is the frequency of its oscillations?
Answer:
I would say your answer is: The frequency of oscillations is 1 HZ { 1 cycle per second}.
The frequency of pendulum oscillations which is 0.25 m long is 1 HZ (1 cycle per second).
What is frequency?The quantity of waves leaving a spot in relation to time is known as its frequency. Hertz units are used to measure frequency. Humans with typical hearing abilities can hear frequencies between 20 Hz and 20 kHz. The frequency is defined mathematically as the time period divided by the factor of one. The number of rotations or vibrations that a body in periodic motion makes in a given amount of time.
A moving disturbance is referred to as a wave. The waves that must pass through a medium like air or water are referred to as mechanical waves. Other forms of waves, such as electromagnetic waves, can pass through both mediums and a vacuum.
Given:
The length of the pendulum, l = 0.25 m,
Calculate the frequency by following the formula:
f = [tex]1/T[/tex] =ω / 2[tex]\pi[/tex]
Therefore, the frequency of pendulum oscillations which is 0.25 m long is 1 HZ (1 cycle per second).
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An owl has a mass of 4.00 kg. It dives to catch a mouse, losing 800.00 J of its GPE. What was the starting height of the owl, in meters?
Answer:
h=20
Explanation:
gpe=mgh
800=4×10×x
x=20 hope it helps
Should Fast Food Companies be held responsible for the obesity problem in the US or any country? Why?
Learning Task No. 3:
Use the diagram showing the relationship among current,
resistance and voltage. Explain the relationship between
current and voltage;
voltage and resistance;
current and resistance.
Write your answer below
Answer:
There is no diagram in this question, however, the question can be answered based on general understanding.
1. current and voltage; direct relationship
2. current and resistance; inverse relationship
3. voltage and resistance; direct relationship
Explanation:
The relationship between current (I), resistance (R) and voltage (V) has been explained by Ohms in his law. In Ohms law, which states that the current flowing through a circuit is directly proportional to the voltage and inversely proportional to the resistance.
This further means that if the voltage (V) increases, then the current (I) also increases and vice versa while if the resistance (R) is increased, the current (I) decreases and vice versa.
The equation represented by this law is:
V = IR or I = V/R or R = V/I
Likewise, the when the resistance is increased, the voltage increases and vice versa.
Therefore;
- Current (I) is directly proportional to the Voltage (V)
- Current (I) is inversely proportional to the Resistance (R)
- Voltage (V) is directly proportional to the Resistance (R)
Put them in order to smallest to largest: centimeter, femtometer, kilometer, light year, meter, nanometer
The circumference of a classroom
clock is 34.5 inches. Find the diameter
of the clock. Round to the nearest
whole number.
Answer:
10.981691073341
So, 11 inches would be the diameter.
Explanation:
Please mark brainliest if correct!
What is it called when an unwanted material that contains radioactive atoms is present on another material?
Answer:
Radioactive contamination
Explanation:
radioactive contamination is when radioactive atoms are present on somethingWhen an unwanted material that contains radioactive atoms is present in another material is known as Radioactive contamination.
What are radioactive atoms?The process of radioactive decay is how an unstable atomic nucleus loses energy through radiation. A substance that has unstable nuclei is regarded as radioactive. Alpha, beta, and gamma decay are three of the most prevalent forms of decay, and they all entail the emission of one or more particles.
According to the statement, "For a given time, the number of nuclei of the elements existing at that moment is exactly proportional to the rate of radioactive decay of an atom." This may be expressed as, where N is the total number of nuclei, d N d t N.
When radioactive particles are deposited on, inside of, or around an individual or a business, nuclear radiation results. When radioactive materials are discharged into the environment, they have the potential to contaminate the air, water, surfaces, soil, plants, buildings, people, and animals.
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What are the reactants in the photosynthesis chemical equation?
The photosynthesis chemical equation states that the reactants
(carbon dioxide, water and sunlight), yield two products, glucose and oxygen gas. The single chemical equation represents the overall process of photosynthesis.
hope this help you!
Does anyone just ever question their gender. But you get scared out of wanting and feeling like the opposite gender.
Yeah it feels weird, it gives me goosebumps. Im a boy actually, but when I think my self as a girl it just cringes me. But I also wonder how would my life would change.
A rubber ball thrown at a speed of 5 m/s hit a flat wall and
returned to the thrower at a speed of 5 m/s. Which
statement correctly describes the momentum of the rubber
ball?
Answer:
See the explanion below
Explanation:
Linear momentum is defined as the product of mass by velocity and can be calculated by the following equation.
[tex]P =m*v[/tex]
where:
P = momentum [kg*m/s]
m = mass [kg]
v = velocity [m/s]
When the ball hits the wall it receives a force for a very short time, this time and force value is known as momentum and can be calculated by the following expression.
[tex]-(m_{1}*v_{1}) + (F*t)=(m_{1}*v_{2})[/tex]
where:
m₁ = mass of the ball [kg]
v₁ = 5 [m/s]
v₂ = 5 [m/s]
v₁ = v₂
[tex]F*t = Imp[/tex]
[tex]Imp = (m_{1}*v_{1})+ (m_{1}*v_{2})\\Imp = 2*m*v_{1}[/tex]
It can be said that the impulse is equal to 2 times the speed of throwing by the mass.
A ball of mass of 0.5kg is dropped from a height of 2m.
Assuming that all of the GPE is transferred to KE, what
will be the velocity of the ball when it hits the ground?
Answer:
6.3m/s
Explanation:
Given parameters:
Mass of the ball = 0.5kg
Height = 2m
Unknown:
Velocity when the ball hits the ground = ?
Solution:
Since the potential energy is transformed into kinetic energy;
P.E = K.E
mgh = [tex]\frac{1}{2}[/tex] m v²
cancelling m;
gh = [tex]\frac{1}{2}[/tex] v²
v² = 2gh
v = √2gh
Insert the parameters and solve;
v = √2gh = √ 2 x 9.8 x 2 = 6.3m/s
A cycler rides 27.0 km in 13 minutes, then 33.0 km in 17 minutes. What is the jogger's average speed in km per minute?
Answer: 9
Explanation: because you would add 13+4=17, then you would add 27+5=33, so then 4+5=9 so there's your answe
Which statement describes how Earth compares to the moon? Earth has more inertia than the moon. The moon has more gravitational pull than Earth. The moon rotates at a constant speed while Earth’s speed varies. Earth and the moon will not change their motion when acted on by a force.
Answer
Earth has more inertia than the moon.
Answer:
A:Earth has more inertia than the moon.
Explanation:
proof:
Thank you for the answer the person on top :)
When the sun first formed, small bodies of matter called _____ surrounded the newly born sun.
Answer: comets
Explanation:
Write your reflection about the three levels of perfection of mahayana Buddhism. Your reflection paper must contain 100 words?............please help me
Answer: Mahayana is a term for Buddhist culture. It is considered as existing branches of Buddhism.
Explanation:
The mahayanas is a major movement typically in the history of Buddhism. It was originated in Northern India. It comprises of many schools. It involves the reinterpretation of the fundamental human beliefs. This also involves the interpretation and teaching of Buddhism.
The three-level of perfection of Mahayana Buddhism are:
generositymorality, andpatienceThese three are mainly related to the virtuous practices for anyone, for a better and happy life in society. There are three more perfections those are-energy, meditation, and wisdom.
Mahanayan is a term under the Buddhist culture and is considered as the present or existing branch of Buddhism. It was originated in Nothern India, which comprises many schools.
The three main perfections state how the human being should live. The perfection of generosity is said as the entryway to dharma, it is the beginning of the aspiration to realize enlightenment for all beings. The perfection of morality guides us until we find our own balance, and the perfection of patience literally means "able to withstand."
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Long-Distance Space Travel
Many scientists and engineers are working toward the goal of sending astronauts to Mars. The trip is estimated to take about 9 months each way. It is very expensive to take enough oxygen to last the whole trip. The astronauts also need enough food, and there has to be a way to get rid of excess carbon dioxide created by their cellular respiration.
Present a plan for the astronauts. Explain how growing food during space flight will help regulate carbon dioxide and oxygen levels. List the supplies the astronauts would need.
Answer:
Green house
Explanation:
You could build a little green house sorta thing bc plants produce oxygen and then the plants you can eat also you are supposed to have water so there s the plants water!
Air. Plants are necessary for the creation of breathable air on Earth. During photosynthesis, plants convert carbon dioxide into oxygen and improve the air we breathe.
What food during space flight help regulate carbon dioxide?They can serve as food or as a cooling environment for astronauts traveling in space. Plants can help regulate cabin humidity by metabolizing atmospheric carbon dioxide to produce useful oxygen.
The crews of human spacecraft may experience psychological benefits from growing plants in space. The ISS could benefit from plant growth by producing oxygen for astronauts to breathe and removing carbon dioxide from the atmosphere.
According to the researchers' findings in their article, eating these fresh foods is also thought to have the additional advantages of reducing stress and boosting morale.
Therefore, The ability to grow vegetables in greenhouses in space could help astronauts supplement their diets.
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What is the speed of a jet plane that flies 8100 km in 27 hours (in km/hr)
Electromagnetic waves differ from other types of waves because they are (2 points)
Group of answer choices
a. a continuous transfer of energy.
b. able to travel through a vacuum.
c. a visible form of energy.
d. able to move particles in a medium.
Answer:
b. able to travel through a vacuum.
Explanation:
The most distinguishing factor of an electromagnetic waves is that they are able to travel through a vacuum.
These waves do not require materials in a medium for propagation.
Electromagnetic waves are formed by the propagation of the electric and magnetic fields. They vibrate at an angle of 90° . They are unlike like mechanical waves that requires that requires materials in medium for their propagation.How fast is a 5 kg object traveling that has 20 kg m/s of momentum?
Answer: 100
Explanation:
Define the term sorting
Answer: arrange systematically in groups; separate according to type, class, etc.
Explanation:
i hooked this up btw
Why hasn't scientific inquiry displace faith, intuition, and dreams?
Answer:
scientific inquiry has not displaced faith, intuition, and dreams. These traditions and ways of knowing have emotional value and provide moral guidance to many people. But hunches, feelings, deep convictions, old traditions, or dreams cannot be accepted directly as scientifically valid.
1. In this activity, you will be looking for a relationship between the mass of the cart and the acceleration of the cart.
Which variable do you need to keep constant during this experiment?
Mass of the cart
The fan force on the cart
The acceleration of the cart
Answer:
Mass of cart
Explanation:
PLEASE HELP ME!!!!
A. The velocity increases during the time periods labeled A and C.
B. The velocity remains constant as the ball bounces.
C. The velocity increases during the time periods labeled B and D.
D. The velocity decreases during all time periods.
Answer:c
Explanation:
Answer:
A. The velocity increases during the time periods labeled A and C.
Explanation:
Gravity causes all falling objects to accelerate at a rate of 98 m/s2.
O True
O False
Which plate undergo subduction at oceanic-continental convergent plate boundaries?Why?
Answer:
Oceanic crust may collide with a continent. The oceanic plate is denser, so it undergoes subduction. This means that the oceanic plate sinks beneath the continent. This occurs at an ocean trench.
Explanation:
What is the centripetal force needed to keep a 3.0kg mass moving in a circle of radius 0.50 m at a speed of 8.0m/s?
Answer:
384N
Explanation:
Given parameters:
Mass = 3kg
radius = 0.5m
Speed = 8m/s
Unknown:
Centripetal force = ?
Solution:
The centripetal force is the inward force that keeps a body in motion along a circular path.
It is mathematically expressed as;
F = [tex]\frac{mv^{2} }{r}[/tex]
m is the mass
v is the speed
r is the radius
Now insert the parameters and solve;
F = [tex]\frac{3 x 8^{2} }{0.5}[/tex] = 384N