Nine elements that have been known since ancient times, and their discovery dates are not precisely recorded are Gold (Au), Silver (Ag), Copper (Cu), Iron (Fe), Lead (Pb), Tin (Sn), Mercury (Hg), Sulphur (S) and Carbon (C).
1. Gold (Au): Gold has been used by humans for thousands of years, with evidence of its use dating back to ancient civilizations like the Egyptians, Sumerians, and Indus Valley people.
2. Silver (Ag): Like gold, silver has a long history of human use and has been mined and utilized for various purposes since ancient times.
3. Copper (Cu): Copper is one of the oldest metals known to humans, and its use dates back over 10,000 years. It was one of the first metals to be smelted and used in tools, weapons, and art.
4. Iron (Fe): Iron is another ancient element that has been used for thousands of years. Early civilizations discovered iron in meteorites and later learned to smelt it from iron ores.
5. Lead (Pb): Lead has been known to humans since ancient times and was used by the ancient Egyptians, Greeks, and Romans. It was widely used in plumbing, as well as for making containers and pigments.
6. Tin (Sn): Tin has been used by humans for thousands of years, mainly in the form of an alloy called bronze (copper-tin alloy), which was crucial for the Bronze Age.
7. Mercury (Hg): Mercury has a long history of use in various cultures for medicinal, alchemical, and decorative purposes.
8. Sulphur (S): Sulfur has been used since ancient times for various purposes, including medicine, bleaching, and as a component in sulfuric acid production.
9. Carbon (C): While the element carbon itself has always existed on Earth, the awareness of its presence and significance as an element is ancient.
These elements were used by ancient civilizations for various purposes such as jewelry, tools, construction, and religious rituals. Their discovery dates are lost in antiquity, as they have been known to humans for thousands of years.
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You are driving up an inclined road. After 3.0 km you notice a roadside sign that indicates that your elevation has increased by 160 m. What is the angle of the road above the horizontal?
Answer:
~3°
Explanation:
x^2 + 0.16^2 = 3^2
x^2 + 0.0256 = 9
x^2 = 8.9744
x = sqrt(8.9744) = 2.99... = ~3
Which of the following accounts for most of an atom's mass?
A. The nucleus
B. Neutrons
C. Protons
D. Electrons
C.protons
Explanation:
sana makatulong :>
I NEED HELP I AM SO CONFUSED, WILL GIVE BRAIN.
A stone is dropped from the roof of a building. It took 5 s for the stone to reach the ground. What is the height of the building?
Answer:
[tex]resolving \: \\ (\downarrow_{ + }) \: s = ut + \frac{1}{2} g {t}^{2} \\ u = 0 ,\: g = 9.81m. {s}^{ - 2} , \: t = 5s \\ s =h= \frac{1}{2} g {t}^{2}, = \frac{1}{2} (9.81){5}^{2}\\=4.9\times25 \\ h=122.6m[/tex]
3.1 Two waves A and B have frequencies 256 Hz and 1024 Hz respectively have amplitude in ratio 3:1 1.What is their ratio of frequencies? Which wave represents a higher pitch
2.which sound is louder
Answer:
1. the one with the raito
2. the one that stubbed their toe
Explanation:
according to newton’s second law, if there is a net force, there will be
Answer:
The object will have an acceleration and the object's velocity will change.
Explanation:
If there is a net force acting on an object, the object will have an acceleration and the object's velocity will change. Newton's second law states that for a particular force, the acceleration of an object is proportional to the net force and inversely proportional to the mass of the object.
PLS MARK BRAINLIEST
Identifying the Parts of an Ecosystem
Animals at a water hole in a barren area. Gazelles are on the near shore, zebras are in the water, and giraffes are at the far edge.
Use the image and the drop-down menus to match the parts of an ecosystem to each description.
All the zebras:
Zebras, gazelle, giraffes, trees:
A giraffe:
Gazelle, zebras, giraffes, water, trees, soil:
Answer:
p c o e
Explanation:
Answer:
Explanation:
pcoe
How is an apple falling from a tree like the potential difference in a battery?
The gravitational potential energy of a falling apple is similar to the potential difference of a battery because both are energy stored in the object
The gravitational potential energy of a falling apple is maximum when the apple is at maximum height. As the apple begins fall to the ground the potential energy decreases and it will be transformed to kinetic energy.
[tex]P.E_i + K.E_i = P.E_f + K.E_f[/tex]
The potential difference in a battery is total energy stored in the battery.
Thus, the gravitational potential energy of a falling apple is similar to the potential difference of a battery because both are energy stored in the object.
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The similarity is that both the battery and the falling apple have stored energy.
We define the potential energy of an object as stored energy in that object.
A battery has potential energy, it is stored until you connect it to something and allow that energy to flow.
Similarly, when the apple is in the air it has potential energy, that will be transformed into kinetic energy as it falls (as the apple falls, its velocity increases, thus, the kinetic energy increases).
So both, the apple and the battery have stored energy, and that is the similarity between these two.
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A silica bulb of negligible expansivity holds 0.3kg of mercury at 00 C when fall. Some steel balls are introduced and remaining space is occupied at 00 C by 250gm of mercury. On heating the bulb and its contents to 1000 C, 5gm of mercury overflow. Find the linear expansivity of the steel.[γ=1.8*10- 6 / 0 C]
Answer:
sorry I don't know the answer for this question
Which of the following wavelengths of light from distant stars and other objects are
observable from the ground? (More than one may be observable)
(a) Ultraviolet (400 to 1 nm wavelength)
(b) Gamma-ray wavelength (0.001 nm and shorter wavelength)
(c) Visible (Optical) (700 to 400 nm wavelength)
(d) X-ray wavelength (1 to 0.001 nm wavelength)
(e) Near-infrared (10 ffm to 0.7 ffm wavelength)
(f) Long-wavelength radio (100 km to 10 m wavelength)
(g) Far- and mid-infrared (about 100 to 10 ffm wavelength)
(h) Intermediate-wavelength radio (10 m to 1 cm wavelength)
(i) Microwave radio (1 cm to about 100 ffm wavelength)
Answer:
its C
Explanation:
its (C)
WHAT FITNESS INJERIES ARE AMOUNG THE EASIEST TO AVIOD
Answer:
eye ,mouth,and,ears face
Answer:
knee, elbow, and wrist
Explanation:
a circuit breaker is tripped when the current in the circuit is greater than 15 A. If the voltage difference is 120, what is the power being used when the circuit breaker is tripped?
Answer:
The answer would be 1800W
Explanation:
P=15a × 120 V
I NEED A SCIENCE EXPERT TO GIVE ME THE RIGHT ANSWERS TO THESE ASAP
Answer:
indepent valuable and random variable
The force between two point-charges of 0.040 C and 0.060 C separated by certain distance is 2.2 x 10^5 N. what is the distance between the charges?
A. 2.5m
B. 5m
C. 10m
D. 20m
Answer:
im in hardvard dont cheat and get good grades and become a graduate
it is c
Explanation:
Answer:
10m
Explanation:
A materiel that allows electricity to flow easily is called an
A materiel that allows electricity to flow easily is called an conductor
If you can please help thanks
Answer:
2
Explanation:
NEED HELP!!!!!!
Which is the BEST description of the role of glucose in the body?
OPTIONS:
A.
It moderates the heartbeat.
B.
It is food converted into fuel.
C.
It regulates body temperature.
D.
It eliminates sugar from the body.
PLEASE NO LINKS
The best description of the role of glucose in the body is that it is the food converted into fuel. Details about role of glucose can be found below.
What is cellular respiration?Cellular respiration is the process by which living organisms obtain energy for their daily activities by breaking down food molecules in their cells.
The food ingested by living organisms is digested into the simplest form called glucose. The glucose is then broken down during cellular respiration.
During cellular respiration, glucose is broken down to produce energy (ATP), which is the fuel for metabolic activities in the body.
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how long would it take to walk around the world
It would take about 8,300 hours to walk around the entire earth without stopping, which in days is 345.83, almost a full year.
Explanation:
I think that full 5 or 6 years
which atmospheric layer has the lowest air pressure?
Answer:
thermosphere!!
Explanation:
thermosphere has the lowest air pressure!!
proposed amendment on no more federal income tax
An individual’s mental predisposition that influences perceptual expectations is one’s perceptual __________. A. bias B. knowledge C. assumption D. set
[tex]▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ { \huge \mathfrak{Answer}}▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ [/tex]
The Correct choice is D
An individual’s mental predisposition that influences perceptual expectations is one’s perceptual set .
A monkey on a raft is crossing a river that flows to the east at 8.0m/s. His top paddling speed is 12.0m/sec. He points due south and attempts to cross. If the river is 120m wide, how far downstream will he end up when he reaches the other side?
The relation of uniform movement allows to find the result for the distance that descended when crossing the river is:
d = 180 m
Given parameters
The velocity of the river [tex]v_r[/tex] = 8.0 m / s towards the East The speed of the monkey [tex]v_m[/tex] = 12.0 m / s towards the south River width x = 120 mTo find
Distance downstream when crossing.
Velocity is a vector magnitude, it has modulus and direction, therefore vector algebra must be used.
The velocities are constant, let's use the uniform motion relation.
v = [tex]\frac{d}{t}[/tex]
In the attached we have a diagram of the movement. Let's calculate the time to cross the river.
[tex]v_r = \frac{x}{t}[/tex]
[tex]t= \frac{x}{v_r}[/tex]
t = [tex]\frac{120}{8.0}[/tex]
t = 15 s
The time is a scalar it is the same for the two movements, let's find how much it has descended in this time.
[tex]v_m = \frac{d}{t}[/tex]
d = [tex]v_m t[/tex]
d = 12.0 15
d = 180 m
In conclusion, using the uniform motion relationship we can find the result for the distance that descended when crossing the river is:
d = 180 m
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Your thumb contains the only saddle joint in the entire body. How would your hand function differently if your thumb contained a pivot joint? What if it contained a ball and socket joint? Describe four consequences of having a different type of joint in the thumb.
P.S. Detailed Response plz
Answer:
The saddle joint allows movement in different directions but only a small amount of rotation. The thumb is the only organ that has a saddle joint.
It should be noted that the bones that are in the saddle joint ensure the back and forth movement of the thumbs.
The pivot joint is the joint that's responsible for ensuring that one bone rotates around another bone. Ball and socket joint can be found in the shoulder and the hip and it allows for greater freedom of movement.
When compared to other movable joints, the saddle joint is prone to dislocation because it's free-moving and rotates on its own axis alone.
In conclusion, if the thumb contained a pivot joint or a ball and socket joint, it'll be able to move more freely.
fun little question,
how many atoms do you think is in a star, i wanna know your answer please share.
Answer:
There is 18
Explanation:
Choose the correct definitions of speed, velocity, and acceleration. Check all that apply. Acceleration tells us in which direction the object is going. Speed is the rate of change of velocity in time. Acceleration is the rate of change of velocity in time. Velocity is used to describe changes in the movement direction of the object. Acceleration tells us how far the object will go in a certain amount of time. Velocity is used to describe how fast the object is moving and tells us in which direction it is going. Speed is used to describe how fast the object is moving. Velocity is the rate of change of speed in time. Speed is used to describe how fast the object is moving and tells us in which direction it is going.
We have thatThe options that define Speed, Velocity,Acceleration.
Speed is used to describe how fast the object is moving.Acceleration is the rate of change of velocity in time.Velocity is used to describe how fast the object is moving and tells us in which direction it is going.Options
B,D,E
From the question we are told
Choose the correct definitions of speed, velocity, and acceleration. Check all that apply.
Acceleration tells us in which direction the object is going. Speed is the rate of change of velocity in time. Acceleration is the rate of change of velocity in time. Velocity is used to describe changes in the movement direction of the object. Acceleration tells us how far the object will go in a certain amount of time. Velocity is used to describe how fast the object is moving and tells us in which direction it is going. Speed is used to describe how fast the object is moving. Velocity is the rate of change of speed in time.Speed is used to describe how fast the object is moving and tells us in which direction it is going.
Generally
Acceleration is the rate of change of velocity in time.Velocity is used to describe how fast the object is moving and tells us in which direction it is going.Speed is used to describe how fast the object is moving without its direction in considerationHence
The options that define Speed, Velocity,Acceleration.
Speed is used to describe how fast the object is moving.Acceleration is the rate of change of velocity in time.Velocity is used to describe how fast the object is moving and tells us in which direction it is going.Options
B,D,E
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an apple has a mass of 2kg. it is 3 m above ground. What is its potential energy?
Answer:
PE = 58.8J
Explanation:
potential energy = mgh
mass = 2kg
g = 9.8m/s^2
h = 3m
A 15 kg chunk of ice falls off the top of an iceberg. If the chunk of ice falls 8m to the surface of the water what is its velocity?
Answer:
When we can get the Kinetic energy from this formula KE= 1/2 M V^2and we can get the potential energy from this formula PE = M g H
we can set that the kinetic energy at the bottom of the fall equals the potential energy at the top so, KE = PE
1/2 MV^2 = M g H
1/2 V^2 = g H
when V is the velocity, g is an acceleration of gravitational force (9.8 m^2/s) and H is the height of the fall (8 m).
∴ v^2 = 2 * 9.8 * 8 = 156.8
∴ v= √156.8 = 12.5 m/s
Physics acceleration
A force of 360 N [East] was applied by a student on a box with a mass of 50 kg.
What is the acceleration of the box if a frictional force of 340 N acts in the
opposite direction?
F = F⁰ - Ff
F = 360 N - 340 N
F = 20 N
F = m × a
20 N = 50 kg × a
a = 20 N / 50 kg
a = 0.4 m/s²
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The acceleration of the box when the frictional force of 340 N is applied to the box will be 0.4 m/s².
What is acceleration?In mechanics, acceleration is the measure of how quickly the velocity of an object changes with respect to time. The magnitude of accelerations as a vector. The acceleration of an object depends on the direction of the net force acting on it.
It is a vector quantity because acceleration has both a magnitude and a direction. Additionally, velocity is a vector quantity. The change in the vector of velocity during a period of time divided by the period of time is the definition of acceleration.
According to the question,
F = F⁰ - [tex]F_f[/tex]
F = 360 N - 340 N
F = 20 N
Force = m × a
20 N = 50 × a
a = 20 N / 50 kg
a = 0.4 m/s²
So, the acceleration of the box will be 0.4 m/s².
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What is The mass of a object that has a force of 100_Newtons and acceleration of 25 m/s/s
Answer:
Yoour MOM
Explanation:
1. Width of A postage stamp is one m, 15 cm, or 20 mm
2. A thickness of ACD 0.1 m 0.01 m or 0.001 m
3. Height of a bus 152.4 mm, 20M, or 250 cm
4 Length of an inch worm 25.4 mm, 25.4 cm or 0.254 m
5. Length of a football field 91.44 m 200 m or one km
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what is atmospheric pressure
Answer:
IN THE EXPLANATION!!
Explanation:
Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth.
Answer:
atmospheric pressure is the pressure exerted on the Earth's surface due to weight of air above it.