Answer:
Explanation:
a )
We shall apply Wein's displacement law
λm x T = b where λm is wavelength of radiation having maximum intensity
T is absolute temperature of body , and b is a constant
b = 2898 μm-K
T = 273 + 34 = 307 K
λm x 307 = 2898
λm = 9.44 μm
= 9440 nm
It is infrared radiation .
b )
We shall apply Stefan's law of radiation.
E = σA T⁴
E is emitted radiation by body acting as black body , A is surface area , T is absolute temperature of body
σ = 5.67 x 10⁻⁸ J / m²T⁴
Surface area of a typical man's body A = 1.9 m²
T = 273 + 34 = 307 K
Assuming human body as black body
E = 5.67 x 10⁻⁸ x 1.9 x 307⁴ J/s
= 9.57 x 10² J/s
= 957 W .
c )
Radiation absorbed
E = 5.67 x 10⁻⁸ x 1.9 x ( 273 + 20 )⁴ J/s
= 794 W .
7. An electric kettle is connected to a mains voltage of 230 V. The current in the kettle is 12 A. Calculate the power of the kettle
Answer:
2,760watts
Explanation:
Power of the kettle = current * voltage
P = IV
Given
I = 12A
V = 230V
Substitute into the formula
Power of the kettle = 12*230
Power of the kettle = 2,760watts
A car traveled a distance of 467.5 km in 5.5 hours . What was its speed in (a) km/h and (b) m/sec ?
Answer:
(a) 85 km/h
(b) 425/18
Explanation:
Use v= d/t
convert km to m
and convert h to s
Explanation:
A car traveled a distance of 467.5 km in 5.5 hours . What was its speed in (a) km/h and (b) m/sec ?
PLZ SOLVE ALL 10
1. What are the six nutrients? Which nutrients provide energy?
2. What percentage of your diet should come from carbohydrates? From protein?
3. What is the primary role of carbohydrates in the body? What are the two major types of carbohydrates?
4. Where does Fiber come from? How much should you consume per day?
5. What is the primary function of protein in the body?
6. What is the primary role of fat in the body?
7. What are the major types of fat? What types of fat are most dangerous to your health?
8. What are vitamins, and why are they important?
9. What are minerals, and why are they important?
10. How much of the human body is made of water? How much fluid should an average person drink each day?
1) Carbohydrates, Lipids (fats), Protein, Vitamins, Minerals, and Water. proteins, fats and carbs provide energy.
2) 45 to 65 percent carbs, and 10-35 percent protein.
3) Carbs are your body's main source of energy. the 2 major types are simple and complex carbs
4) cereals, fruits and vegetables. You should have 25 to 30 grams a day.
5) It helps repair and build your body's tissues, allows metabolic reactions to take place and coordinates bodily functions.
6) It gives you energy and supports cell growth.
7) Saturated fats, Trans fats, Monounsaturated fats, and Polyunsaturated fats. trans fats are the most dangerous for your health
8) Vitamins and minerals are considered essential nutrients, They help shore up bones, heal wounds, and bolster your immune system. They can also help convert food into energy.
9) Minerals help build strong bones to transmitting nerve impulses. Some minerals are even used to make hormones or maintain a normal heartbeat.
10) 60% is made of water, 11 to 15 cups of water should be drank a day.
hope this helps :)
it is a line that intersects a circle at exactly two points.
Secant is the answer. Please mark brainliest.
A line that intersects a circle at exactly two points is called a secant line.
hope this helped!
A force of 350 N is applied to an object that accelerated at a rate of 5 m/sec2. What is the mass of the object
Answer:
7/ m5sec per minute ckvhxrsuvj
Define :density٬archimedes principle
Answer:
density is defined as the amount of mass contained in unit volume of a body .its si unit is kg/m*3
Answer:
Density is the amount of mass per unit volume of a substance.
Archimedes principle states that"When a body is totally or partially immersed in a liquid,it experience an upthrust which is equal to the weight of the liquid displaced"
A 16 g ball at the end of a 1.4 m string is swung in a horizontal circle. It revolves once every 1.09 s. What is the magnitude of the string's tension?
Answer and I will give you brainiliest
Answer:
6.56
Explanation:
frequency = 1/1.09 = 0.92 Hz
f = 1/(2L) × √T/m
0.92 = 1/2(1.4) × (√T/√16)
0.92 = 0.36 × (√T)/4
multiply all through by 4
3.68 = 1.44 × √T
√T = 3.68/1.44 = 2.56
T = 2.56² = 6.56
The magnitude of the string's tension as it is swung in a horizontal circle is 0.744 Newton
Given the data in the question;
Mass of the ball;[tex]m = 16g = 0.016kg[/tex]String is swung in a horizontal circle, Radius; [tex]r = 1.4m[/tex]Period of revolution; [tex]T = 1.09s[/tex]Magnitude of the string's tension; [tex]F_T = ?[/tex]First, we need to get magnitude of the centripetal acceleration:
[tex]a_c = \frac{4\pi ^2r}{T^2}[/tex]
We substitute in our given values
[tex]a_c = \frac{4\pi ^2\ *\ 1.4m}{(1.09s)^2} \\\\a_c = 46.519 m/s^2[/tex]
Now, from Newton's Second Law of Motion:
[tex]F = m\ * \ a[/tex]
Where F is the force, m is the mass of the object and a is the acceleration
We substitute into the equation to get the magnitude of the string's tension.
[tex]F = 0.016kg \ *\ 46.519m/s^2[/tex]
[tex]F = 0.744 kg.m/s^2\\\\F = 0.744 N[/tex]
Therefore, the magnitude of the string's tension as it is swung in a horizontal circle is 0.744 Newton
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6th grade science I mark as brainliest (can someone answer my other question like this?)
Answer:A: July
B: July and august
C:true
Explanation:
To attain the maximum range a projectile has to be launched at 45 degrees if the landing spot and the launch spot are at the same height (neglecting air resistance effects.) Explain in a few sentences how the relation between the vertical and the horizontal components of the initial velocity affects the projectile range
Answer:
see that the velocities are the components in a Cartesian system
Explanation:
The horizontal velocity of the projectile is the x-axis component of the initial velocity
v₀ₓ = v₀ cos 45
vertical speed is
[tex]v_{oy}[/tex] = v₀ sin 45
therefore we see that the velocities are the components in a Cartesian system
What happens when a mixture is formed?
Answer:
Explanation:
A mixture can usually be separated back into its original components. Some examples of mixtures are a tossed salad, salt water and a mixed bag of M&M's candy.
A person in car slides to the right when going through a very sharp left turn on the highway. Is that law of inertia or law of acceleration?
Answer:
Inertia :)
Explanation:
Why do mountain climbers bring thick jackets when they go up the mountain?
A. The altitude increases as the temperature increases.
B. The altitude decreases as the temperature increases.
C. The temperature increases as the altitude increases.
D. The temperature decreases as the altitude increases.
Answer:
letter d is the right answer
Answer:
your answer is option B(The altitude decreases as the temperature increases.)Explanation:
hope it's helpful to you
have a great day ahead
41. Electric and magnetic forces can both make certain objects move. For example, a positively charged particle will repel another positively charged particle. Which of these is the best way for a student to demonstrate the same principle using magnets?
Answer:
Place the north pole of a magnet next to the north pole of another magnet.
Explanation:
Looking at the comments, we can see that the options are:
Place the south pole of a magnet next to the north pole of another magnet.
Place the north pole of a magnet next to the north pole of another magnet.
First, we know that a positively charged particle will repel another positively charged particle.
The same thing happens for magnetic forces (usually we define a magnetic flow from the south pole to the north pole, so we can define the south pole as the "positive" and the north pole as the "negative", but this is only notation and do not really matter), a south pole of a magnet will repel another south pole of a magnet (and the same happens for the north poles)
Then the correct option is:
Place the north pole of a magnet next to the north pole of another magnet.
8.
Billiard ball A, mass 0.17 kg, is moving due east with a velocity of 4.0
m/s. It strikes stationary billiard ball B, which has the same mass. After
the collision, ball A moves at an angle of 30° north of east with a
velocity of 3.5 m/s. Ball B moves at an angle of 60° south of east.
What is the speed of ball B?
Answer:
2 m/s
Explanation:
The momentum of the colliding system is conserved . Therefore, the velocity of the ball B with the same mass as A is 0.52 m/s.
What is momentum ?Momentum of a body is the ability to bring the applied force makes maximum displacement. it is the product of mass and velocity. For a collision, the sum of initial momentum of the two bodies is equal to the sum of their final momentum.
Thus, u be the initial velocity and v be the final velocity.
Then, m1 u1+ m2 u2 = m1 v1 + m1 v2
m1 = 0.17 kg
u1 = 4 m/s
m2 = 0.17 kg
u2 = 0
Then initial momentum = 0.17 × 4 m/s + 0 = 0.68 kg m/s
v1 = 3.5 m/s
0.68 kg m/s = (0.17 × 3.5 m/s ) + (0.17 × v2)
then v2 = 0.52 m/s.
Therefore, the velocity of ball B after collision will be 0.52 m/s.
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A meteor falls from the sky to the Earth. The meteor already had an initial velocity downward when it
was spotted. If it hit the Earth at 335 m/s after being seen for 30 seconds, then what was the initial
velocity of the meteor?
a=9.8
if a wave passes every 17.4 seconds, what is the frequency?
Answer:
to be completely honest I have no idea however I tried calculating it on a calculator and umm...
I think the frequency is...
17,229,452
but ya know I could be totally wrong so if I am sorry
Two objects exert a gravitational force of 3 N on one another when they are 10 m apart. What would that forced be if the distance between the two objects were reduced to 5 m?
Answer:
New force = 12 N
Explanation:
The gravitational force between two masses is given by :
[tex]F=\dfrac{Gm_1m_2}{d^2}[/tex]
Where
d is the distance between masses
Initial force, F₁ = 3 B
Initial distance, d₁ = 10 m
Final distance, d₂ = 5 m
According to the above relation,
[tex]\dfrac{F_1}{F_2}=\dfrac{r_2^2}{r_1^2}\\\\F_2=\dfrac{F_1r_1^2}{r_2^2}\\\\F_2=\dfrac{3\times 10^2}{5^2}\\\\F_2=12\ N[/tex]
So, the new force is 12 N.
What acceleration did you measure from the video? Does this match the acceleration you calculated in the first step?
Explanation:
dont know so sorryyyyyyyyy
How does the energy in a system of magnets change when two magnets repel and move away from each other
A 15 kg mass is lifted to a height of 2m. What is gravitational potential energy at this position
Answer: 294J
Explanation:
[tex]U_g=mg(y_f-y_i)[/tex]
[tex]U_g=(15)(9.8)(2-0)=294J[/tex]
Answer:
294.3 J
Explanation:
U = mgh
U = energy
m = mass
g = gravity
h = height
so
U = 15kg * 9.81 m/s^2 * 2m
294.3 J (joules) [kg *m^2/s^2]
What color is seen when cyan light is shown on magenta paper
Answer:
blue
You see white. What happens when you shine cyan light on a magenta shirt? You see blue.
Explanation:
17. If ice has a density of 0.92g/cm?, what is the mass of a 30 cm block?
I
Answer:
Mass = 27.6 grams
Explanation:
Given the following data;
Density of ice = 0.92g/cm³
Volume = 30cm³
To find mass of ice;
Density can be defined as mass all over the volume of an object.
Simply stated, density is mass per unit volume of an object.
Mathematically, density is given by the equation;
[tex]Density = \frac{mass}{volume}[/tex]
Making mass the subject of formula, we have;
[tex] Mass = density * volume [/tex]
[tex] Mass = 0.92 * 30 [/tex]
Mass = 27.6 grams
Therefore, the mass of ice is 27.6 grams.
How is an electromagnetic field produced? Please I need answers
Answer:
by potential difference and electron gun
Explanation:
a magnetic field is produced whenever an electrical charge is in motion. The spinning and orbiting of the nucleus of an atom produces a magnetic field as does electrical current flowing through a wire. The direction of the spin and orbit determine the direction of the magnetic field.
Answer:
Electromagnetic field can be produced by the superposition of electric field and magnetic field.
Explanation:
What is superposition ?When two or waves propagate in a medium without affecting each other , then at any instant the displacement of a particle will be equal to the vectorial sum of the displacements due to the waves.
Electromagnetic field can be produced by electric arc.It cab be produced by LC Circuits.Hence Electromagnetic field can be produced by L-C CIRCUITS.
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when the body said to be in equilibrium
Answer:
Oh! I just learned abt this
Explanation:
the body is said to be in equilibrium if it is resting or moving with uniform velocity.
Answer: The body is said to be in balance if it is at rest or moving at a uniform speed. In other words, if the body's linear and angular acceleration is zero, the body is said to be in balance. 1
How tall is Mount Everest?
Answer: 29,035 feet
Explanation:
Which of the following laws explains why a net force of 950,000 N is needed at takeoff to accelerate the
530,000 kg Atlas V rocket carrying the rover at a rate of 1.8 m/s2?
A
Newton's third law of motion
B
conservation of momentum
С
Newton's second law of motion
D
Newton's first law of motion
Answer:
Newton's second law of motion
I have a voltage source of 12V but a light that only burns at 5V. The lamp works on 18 mA. Calculate the resistance that you EXTRA have to include in this series connection.
Answer:
The resistance that will provide this potential drop is 388.89 ohms.
Explanation:
Given;
Voltage source, E = 12 V
Voltage rating of the lamp, V = 5 V
Current through the lamp, I = 18 mA
Extra voltage or potential drop = 12 V - 5 V = 7 V
The resistance that will provide this potential drop (7 V) is calculated as follows:
[tex]R = \frac{V}{I} = \frac{7 \ V}{18 \times 10^{-3} A} \ = 388.89 \ ohms[/tex]
Therefore, the resistance that will provide this potential drop is 388.89 ohms.
A person is standing on a level floor. His head, upper torso, arms, and hands together weigh 458 N and have a center of gravity that is 1.34 m above the floor. His upper legs weigh 120 N and have a center of gravity that is 0.766 m above the floor. Finally, his lower legs and feet together weigh 89.8 N and have a center of gravity that is 0.204 m above the floor. Relative to the floor, find the location of the center of gravity for the entire body.
Answer:
the location of the center of gravity for the entire body is 1.08 m
Explanation:
Given the data in the question;
w1 = 458 N, y1 = 1.34 m
w2 = 120 N, y2 = 0.766 m
w3 = 89.8 N, y2 = 0.204 m
The location arrangement of the body part is vertical, locate the overall centre of gravity by simply replacing the horizontal position x by the vertical position y as measured relative to the floor.
so,
[tex]Y_{centre of gravity}[/tex] = (w1y1 + w2y2 + w3y3 ) / ( w1 + w2 + w3 )
so we substitute in our values
[tex]Y_{centre of gravity}[/tex] = (458×1.34 + 120×0.766 + 89.8×0.204 ) / ( 458 + 120 + 89.8 )
[tex]Y_{centre of gravity}[/tex] = 723.9592 / 667.8
[tex]Y_{centre of gravity}[/tex] = 1.08 m
Therefore, the location of the center of gravity for the entire body is 1.08 m
I have a voltage source of 12V but a light that only burns at 5V. The lamp works on 18 mA. Calculate the resistance that you EXTRA have to include in this series connection.
Answer:
The resistance that will provide this potential drop is 388.89 ohms.
Explanation:
Given;
Voltage source, E = 12 V
Voltage rating of the lamp, V = 5 V
Current through the lamp, I = 18 mA
Extra voltage or potential drop, IR = E- V
IR = 12 V - 5 V = 7 V
The resistance that will provide this potential drop (7 V) is calculated as follows:
IR = V
[tex]R = \frac{V}{I} = \frac{7 \ V}{18 \times 10^{-3} A} \ = 388.89 \ ohms[/tex]
Therefore, the resistance that will provide this potential drop is 388.89 ohms.
proof that the kinetic energy of a moving body is half mv square
Answer:
1
Explanation: