Answer:
A blackbody, or Planckian radiator, is a cavity within a heated material from which heat cannot escape. No matter what the material, the walls of the cavity exhibit a characteristic spectral emission, which is a function of its temperature.
Example:
Emission from a blackbody is temperature dependent and at high temperature, a blackbody will emit a spectrum of photon energies that span the visible range, and therefore it will appear white. The Sun is an example of a high-temperature blackbody.
They confessed their guilt.
Answer:
heyyy
May I Know the full question
A boy pulls his toy on a smooth horizontal surface with a rope inclined at 60 degree to the horizontal if the effective force pulling the toy along the horizontal surface is 5 Newton calculate the tension in the rope
Answer:
Tension = 2.5 N
Explanation:
Given:
Angle = 60°
Force f = 5 N
Find:
Tension
Computation:
Tension = fcosθ
Tension = (5)cos60
Tension = (5)(1/2)
Tension = 2.5 N
A car moving round a circular racing track takes 120s to do a lap of 8km what is the speed in km/hr.
Answer:
Solution in photo
Explanation:
A car moves around in a circular racing track, and it takes 120 seconds to do a lap of 8 km, so the speed in km/hr is 239.76 km/hr.
What is Speed?The speed of an object, commonly known as v in mechanics, is a scalar quantity that corresponds towards the size of the change in that object's position over duration or the size of the change in that object's position per unit of time.
The instantaneous velocity is the absolute maximum of the average speed as the time interval's duration gets closer to zero. The cruising pace of an object in a time interval is calculated by dividing its distance traveled by the time interval's duration. Velocity and speed are different concepts.
The given data according to the question is,
Time, t = 120 s
Distance, d = 8 km
s = 8/120
s =0.0666 km/sec or
s = 0.0666/1s × 3600
s = 239.76 km/hr.
Therefore, the speed is 239.76 km/hr.
To know more about Speed:
https://brainly.com/question/312131
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In 1630 at the beginning of European settlement, about 425,000,000 hectares of the United States were covered with trees. By 2017, the area covered by trees was reduced to 300,000,000 hectares. What is the percentage decrease in the area covered by trees between 1630 and 2017?
Answer:
29.41%
Explanation:
Given that,
In 1630 at the beginning of European settlement, about 425,000,000 hectares of the United States were covered with trees.
By 2017, the area covered by trees was reduced to 300,000,000 hectares.
We need to find the percentage decrease in the area covered by trees between 1630 and 2017.
The percentage decrease in any value is given by :
[tex]\%=\dfrac{300,000,000 -425,000,000 }{425,000,000 }\times 100\\\\=29.41\%[/tex]
So, the percentage decrease in the area covered by the trees is 29.41%.
Which statement about the relationship between air pressure and air density is accurate?
A) Air pressure decreases as air density increases
B) Air pressure increases as air density increases
C) Air pressure increases as air density decreases
D) Air pressure is unrelated to air density
Answer:
A: Air pressure decreases as air density increases
Explanation:
Pressure is a force exerted on or against an object by being in contact with a substance. Thus, air pressure is due to the bombardment of the air (gas) particles with a surface. Density is defined as the mass per volume of a substance. Thus, air density is defined as the mass of air per unit volume.
If that Explanation does not make any sense let me make it easier.
The air at the top of a mountain is cooler than the air at the bottom. This temperature difference is due to a phenomenon that occurs in Earth’s atmosphere. Air rises and sinks based on differences in temperature and pressure. Here’s a quick experiment that will help explain the role of pressure.Take in a deep breath as if you were ready to blow out birthday candles. Puff your cheeks with air like a chipmunk. Hold it for a few seconds, and then blow the air slowly from your cheeks.Cold air sinks while warm air rises because cold air is denser than warm air. When a lot of cold air sinks, it creates an area of high air pressure where it hits the surface. This high-pressure air flows to an area of low pressure, creating wind. When this air warms, it rises up into the atmosphere.Temperature decreases as altitude increases. That’s why a mountain peak may be covered with snow while the bottom of the mountain is full of green plants and trees. When warm air rises into the atmosphere, it cools. The density of the air increases as it cools, which eventually creates an area of high pressure and starts the cycle again.
If not for this phenomenon of air rising and sinking in the atmosphere, there would be no wind or weather.
I hope that helped!
what are parallel circuits?
Answer:
have two or more paths
Explanation:
A parallel circuit is one that has two or more paths for the electricity to flow, the loads are parallel to each other.
What is always true about the light ray that emerges from the right side of the lens?
A Force that does not change an object velocity
Answer:
I think ur wrong to say force doesn't change an object velocity
Explanation:
Force affects how objects move. They change the direction of motion of an object that is already moving. Since force causes a change in the speed or direction of an object, we may say that force causes changes in an object velocity.
How much distance does a car travel if it is driving down the road at 50 m/s before hitting
the gas and accelerating at 3 m/s2 for 20 seconds?
Answer:
from second equation of motion
[tex]S = ut + \frac{1}{2} a {t}^{2} \\ S = (50 \times 20) + (\frac{1}{2} \times 3 \times {20}^{2} ) \\ S = 1000 + 600 \\ S = 1600 \: m[/tex]
PHYSICS PLEASE HELP
a. Draw a force diagram
b. The skier has a mass of 76.6 kg and the coefficient of kinetic friction between the skier and the snow is 0.15. The angle the hill makes to the horizontal is 38 degrees and the distance the skier glides down the hill is 40.5 m. Answer the following questions based on this information.
What is the magnitude of the normal force on the skier as they glide down the hill? Show your work.
c. What is the magnitude of the force of friction on the skier as they glide down the hill? Show your work.
d. What is the acceleration of the skier as they glide down the hill? Show your work.
e. What is the speed of the skier when they reach the end of the straight section of the hill? Show your work.
f. How many seconds does the skier take to reach the end of the straight section of the hill? Show your work.
Answer:
Explanation:
b )
Normal force R = mgcosθ
= 76.6 x 9.8 x cos 38
R = 591.5 N
c )
Force of friction
= μ R
μ is coefficient of friction .
= .15 x 591.5
= 88.73 N
d )
Net force
= mg sinθ - friction
= 76.6 x 9.8 x sin 38 - 88.73
= 462.16 - 88.73
= 373.43 N
Acceleration = 373.43 / 76.6
a = 4.87 m / s²
e )
v² = u² + 2 a s
s = 40.5 m
a = 4.87
u = 0
v² = 0 +2 x 4.87 x 40.5
= 394.5
v = 19.86 m /s
f )
v = u + a t
19.86 = 0 + 4.87 t
t = 4 .07 s
identify the types of simple machine given below .
a)scissors b)axe c)driller
Answer:
there should some picture to identify right?
pls edit your question and insert the picture..
Answer:
Well it depends Because An axe Would be A Simple machine well as a drill is
If you and your friend are playing tug of war and both are you are pulling with the same amount of force. What will happen?
Answer:
Nothin will move, it will stay the same since no force is greater than the other. it's "the same amount of force" which also means an equal amount of force
Explanation:
The forces are only equal if there is no acceleration (which in the game of tug of war, accelerating yourself and your opponent is the idea). If the force on the rope and the ground are both equal either nothing moves or some other force is being applied in the system.
Hope this helped!
A 1 kg box is sitting on a flat horizontal surface that has a coefficient of static friction value of 0.8. What answer best states the minimum force required to move the box in the horizontal direction?
A. >-9.8N
B. >9.8N
C. >7.84N
D. >9N
The normal force felt by the box has magnitude
F[normal] = (1 kg) g = 9.8 N
so that the maximum magnitude of static friction is
F[s. friction] = 0.8 F[normal] = 7.84 N
In order to get the box to move, (C) a minimum force of 7.84 N is required.
A 150 lb person and a 200 lb person run into each other.
What can you say about force?
Who accelerated the most? Why?
Explanation:
1. Force is something that pushes or pulls you
2. The 150 lbs person accelerated faster because they had less force pushing or pulling them down.
An apple in a tree has a mass of 0.21 kg. If it is 7.2 meters above the ground, how much potential energy does it have?
Answer:
14.8J
Explanation:
PE=MGH
M=0.21
G=9.8m/s
H= 7.2 m
0.21x7.2x9.8= 14.8176 J
What does anaerobic mean?
A. Short bursts of energy
B. Without oxygen
C. Intense physical output
D. With oxygen
Answer:
without oxygen because
Answer:
Without oxygen
Explanation:
Please Help Me!!!!!!
Answer:
..
Charcoal is flammable.
An object completes 10 cycles in 50s.
a. What is the period of its rotation?
b. What is the frequency of its rotation?
Answer:
.
Explanation:
Explanation:
Given parameters:
Number of cycles = 10cycles
Time taken = 50s
Unknown:
Period of its rotation = ?
Frequency of its rotation = ?
Solution:
The period of rotation is the time taken time taken for a body to complete a number of rotation;
Period = [tex]\frac{t}{n}[/tex]
t is the time
n is the number of cycles
Period = [tex]\frac{50}{10}[/tex] = 5s
The period is 5s
Now, frequency is the inverse of period;
F = [tex]\frac{1}{period}[/tex] = [tex]\frac{1}{5}[/tex] = 0.2Hz
Which of the following statements about Copernicus' heliocentric model of the Solar System are accurate?
It was the first such model was supported by scientific evidence.
It was not published until Copernicus was close to death.
It was the first time a heliocentric model had ever been suggested.
It was not controversial, and was readily accepted.
It stated that the Sun revolved around the Earth.
It stated that the Earth revolved around the Sun.
Answer:
(i) It was the first such model was supported by scientific evidence: FALSE
(ii) It was not published until Copernicus was close to death: TRUE
(iii) It was the first time a heliocentric model had ever been suggested: FALSE
(iv) It was not controversial, and was readily accepted: FALSE
(v) It stated that the Sun revolved around the Earth: FALSE
(vi) It stated that the Earth revolved around the Sun: TRUE
Explanation:
We proceed to demonstrate the validity of each option from statement:
(i) It was the first such model was supported by scientific evidence: FALSE
The geocentric model was based mostly on interpretation of two astronomical findings: (a) The displacement of the stars with respect to Earth due to stellar parallax, (b) The apparent consistency of brightness of the planet Venus seen from Earth.
(ii) It was not published until Copernicus was close to death: TRUE
Copernicus published his heliocentric theory, contained in the book De revolutionibus orbium coelestium, months before his death, in 1543.
(iii) It was the first time a heliocentric model had ever been suggested: FALSE
Greek mathematician and astronomer Aristarchus of Samos was the first person who proposed the heliocentric model in the 4th Century.
(iv) It was not controversial, and was readily accepted: FALSE
The Roman Catholic Church defended geocentric model proposed by Claudius Ptolemy and Tycho Brahe and rejected the model proposed by Copernicus, whose publication was included in the Index Librorum Prohibitorum in 1616.
(v) It stated that the Sun revolved around the Earth: FALSE
This is the main idea of the geocentric model.
(vi) It stated that the Earth revolved around the Sun: TRUE
This is the main idea of the heliocentric model.
Deanna's niece loves to swing at the local playground, so Deanna takes her and pushes her on the swing. Deanna must use (motion / transfer / force / energy) to exert a (transfer / motion / force / energy) that causes the swing to change (force / energy / motion / transfer/position).
AnswerShe uses force and air
Explanation:
n bhvygvg gv
Plants appear green because they do not absorb the green wavelengths of light. What happens to those green light waves when they hit a plant? The are diffracted. They are absorbed. They are reflected. They are refracted.
Answer:
They are reflected.
Explanation:
Red light is absorbed while green light is reflected, causing the color to be green in human eyes.
Answer:
C
Explanation:
Tom drives on a highway and never changes his speed for the whole journey. He drives for 300 miles and it takes him 5 hours. What is Tom's speed on the highway?
Answer:
QESARDFRGTSRTATFREVERSRvrvqwqv
Explanation:
vfqfvcafbraf w rfdsd AEWvd a
A ray of light travelling in air enters obliquely into water. Does the light ray bends towards the normal or away from the normal? Why?
Explanation:
The refraction index of water (1.33) is higher than air (1), therefore the light ray will bend towards the normal.
If a car traveled 60 m in 30 s, what is the velocity?*
Answer:
6.56168
Explanation:
What is the average speed of this car over the entire journey ?
Answer: 0.83333333333 km/h
Explanation: give brainliest
What causes the electrons to move in the “Electromagnetic Induction” animation?
a.
Current
c.
Changes in magnetic field
b.
Voltage
d.
Kinetic energy
Please select the best answer from the choices provided
A
B
C
D
Answer:
Change in the magnetic field
A 1000 kg car’s velocity increases from 5 m/s to 10 m/s. What is the change to the car’s kinetic energy? Show your work.
Answer:
k. e. = 1/2 mv^2
1/2 * 1000 * (5)^2
1/2 * 1000 * 25
12500 joules
k. e. = 1/2 mv^2
1/2 * 1000 * (10)^2
1/2 * 1000 * 100
50000
change in k. e. = final - initial
50000 - 12500
= 37500 joules
hope it helps you
how can an object travel 6 meters if it ends up at -2 on the number line?)
Answer: Distance is a scalar quantity and direction is not applicable. We can use graphs to depict an object's change in position over time. Create a large number line in the classroom by taping index cards on the floor or wall 1 meter apart.
Explanation: I really hope that was helpful.
a pulley is used to lift a 2000 N safe over frosty's head. the safe is lifted 6m in 4s by Rudolph. how much power did Rudolph use?
Answer:
3000W
Explanation:
Given parameter:
Weight of safe = 2000N
Height of lift = 6m
Time = 4s
Unknown:
Power used by Rudolph = ?
Solution:
Power is the rate at which work is being done. It is expressed as:
Power = [tex]\frac{Work done }{Time taken}[/tex]
Work done = Weight x height = 2000 x 6 = 12000J
Power = [tex]\frac{12000}{4}[/tex] = 3000W
14. How do speed and velocity differ?
Answer:
Speed is the time rate at which an object is moving along a path, while velocity is the rate and direction of an object's movement. Put another way, speed is a scalar value, while velocity is a vector.
Explanation: