Answer:
Explanation:
he SI rests on a foundation of seven (7) defining constants: the cesium hyperfine splitting frequency, the speed of light in vacuum, the Planck constant, the elementary charge (i.e. the charge on a proton), the Boltzmann constant, the Avogadro constant, and the luminous efficacy of a specified monochromatic source. Definitions of all seven (7) SI base units are expressed using an explicit-constant formulation and experimentally realized using a specific mises en pratique (practical technique).
The seven SI base units, which are comprised of:
Length - meter (m)
Time - second (s)
Amount of substance - mole (mole)
Electric current - ampere (A)
Temperature - kelvin (K)
Luminous intensity - candela (cd)
Mass - kilogram (kg)
The International System of Units (SI), commonly known as the metric system, is the international standard for measurement. The International Treaty of the Meter was signed in Paris on May 20, 1875 by seventeen countries, including the United States and is now celebrated around the globe as World Metrology Day. NIST provides official U.S. representation in the various international bodies established by the Meter Convention: CGPM - General Conference on Weights and Measures; CIPM - International Committee for Weights and Measures; and BIPM - The International Bureau of Weights and Measures.
The SI is made up of 7 base units that define the 22 derived units with special names and symbols. The SI plays an essential role in international commerce and is commonly used in scientific and technological research and development. Learn more about the SI in NIST SP 330 and SP 811.
Resources for Students and Teachers
Redefining the SI – In November 2018, the world’s measurement experts voted and unanimously approved a revision of the SI that establishes a measurement system entirely based on physical constants of nature. The changes became effective on World Metrology Day, May 20, 2019. (NIST)
Learn more about the Road to the Revised SI. Learn more about the SI Redefinition.(NIST)
The Last Artifact documentary and companion Grade 5 to 12 educational resources, which document the work that went on behind the scenes to modernize the International System of Units (SI). (Montana PBS)
NIST SP 1247 SI Base Units Relationships Poster – a colorful poster illustrating the relationships of the International System of Units (SI) derived units with special names and symbols and the seven traditional base units. (NIST)
Metric Trivia Quiz – How much do you know about the metric system (SI)? Try the NIST Metric Trivia Quiz online or use the Alexa skill to test your knowledge and be on your way to thinking metric! (NIST)
SI Education and Training – Explore NIST metric system education resources that build SI measurement system familiarity and fluency. (NIST)
Kids Education Resources. (NIST)
Busting Myths about the Metric System. (NIST Taking Measure Blog)
Resources
Becoming Familiar with SI
Everyday Estimation
Metrication FAQs
Prefixes
SI Publications
Understanding Metric
Writing with Metric Units
Answer:
International System of Units??
If a student is sitting in their chair and the leg of the chair breaks the student will __________ toward the floor because the gravity is a greater force.
A.Accelerate
B.Force
C.Balance
D.Speed
Answer:
theyll accelerate towards the floor :)
How does an increase in thermal energy affect the particle motion in each state of matter?
Answer:
Explanation:
A rise in temperature increases the kinetic energy and speed of particles; it does not weaken the forces between them. The particles in solids vibrate about fixed positions; even at very low temperatures. Individual particles in liquids and gases have no fixed positions and move chaotically.
A man is standing on the edge of a 20.0 m high cliff. He throws a rock horizontally with an initial velocity of 10.0 m/s. How long does it take to reach the ground? How far does the rock land from the base of the cliff?
Answer:
d = 20.2 m
t = 2.02 s
Explanation:
Horizontal Motion
When an object is thrown horizontally with a speed v from a height h, it describes a curved path ruled by gravity until it hits the ground.
To calculate the time the object takes to hit the ground, we use the equation:
[tex]\displaystyle t=\sqrt{\frac{2h}{g}}[/tex]
Note the time does not depend on the initial speed.
The range or maximum horizontal distance traveled by the object can be calculated as follows:
[tex]\displaystyle d=v.t[/tex]
The man standing on the edge of the h=20 m cliff throws a rock with a horizontal speed of v=10 m/s.
The time taken by the rock to reach the ground is:
[tex]\displaystyle t=\sqrt{\frac{2*20}{9.8}}[/tex]
[tex]\displaystyle t=\sqrt{4.0816}[/tex]
t = 2.02 s
Now for the horizontal range:
[tex]\displaystyle d=10\cdot 2.02[/tex]
d = 20.2 m
a parachutist decided to jump of a plane calculate how far does he travels in 2 seconds knowing that he started at rest and accelerates downward at 10ms
Answer:
20 meters
Explanation:
Given the following parameters
Time t = 2 seconds
Acceleration a = 10m/s²
Required
Distance covered S
Since the body started from rest, u = 0m/s
Using the equation of motion S = ut + 1/2 at²
Substitute
S = 0 + 1/2(10)(2)²
S = 5 * 2²
S = 5 * 4
S - 20m
Hence he travels 20 meters
What type of bond is formed when a metal from group 2 reacts with a nonmetal from group 6
Answer:
The correct answer is Ionic Bond
Explanation:
Group 2 elements are majorly metals, which include Magnesium (12), calcium (20), and some other metals, while the nonmetal from group 6 includes Oxygen (8), sulfur (16). The nonmetal gain electrons from the metal.
When metals in group two combine with nonmetal in group 6 they form an Ionic bond which is a strong bond.
The remaining electrons in the outer shell are transferred when the oppositely charged ions of both elements combined. Where the metal transfers electrons to the nonmetal. For example, Magnesium (Mg) + Oxygen (O) = MgO. Magnesium transfers its (2) outer electrons to oxygen.
A bicyclist is finishing his repair of a flat tire when a friend rides by with a constant speed of 3.5 m>s. Two seconds later the bicyclist hops on his bike and accelerates at 2.4 m>s2 until he catches his friend. (a) How much time does it take until he catches his friend
Answer:
4.28 s
Explanation:
after two seconds (2 s) His friends is
d = 3.5 m/s x 2 s = 7 meter ahead.
in this state, a bicylist start from initial velocity vo = 0 m/s and accelerat 2.4 m/s²
then, when bicylist reach his friend
t friend = t bicyclist = t
d bicylist = d friend + d
-------
d friend = 3.5 . t
d bicylist = vo . t + ½ a t²
d friend + d = vo . t + ½ a t²
3.5 t + 7 = 0 . t + ½ . 2.4 . t²
3.5 t + 7 = 1.2 t²
0 = 1.2 t² - 3.5 t - 7
t = -1.363 and t = 4.28
take the positive one
Find the acceleration if the force is 10,000 N and the mass is 500 kg.
Answer:
20m/s²
Explanation:
Given parameters:
Force = 10000N
Mass = 500kg
Unknown:
Acceleration = ?
Solution:
According to Newton's second law of motion:
Force = mass x acceleration
Mass is the amount of matter in a substance
Acceleration is the rate of change of velocity with time
Now insert the parameters and solve;
10000 = 500 x acceleration
Acceleration = 20m/s²
Define relative motion??
Answer:
The laws of physics which apply when you are at rest on the earth also apply when you are in any reference frame which is moving at a constant velocity with respect to the earth. For example, you can toss and catch a ball in a moving bus if the motion is in a straight line at constant speed.
Explanation:
A truck weighs 500 N on Earth. What's the mass of the truck?
O 5 Kg
O 50 Kg
500 kg
500 N
PLEASE HURRY
Answer:
Solution given:
Wight [W]=500N
gravity [g]=10m/s²
mass[m]=?
we have
W=mg
500=m*10
m=500/10
m=50kg
the mass of the truck is 50kg.
audeze oriented physics professor drives 3.25 km North than 4.75 km west and then 15 km South find the magnitude and direction of the resultant vector
Answer:
first lets do the anti parralel part of forces
we get 18. 25-15 =3.25 to north
then ww use phytagores theorem
3.25^2+4.75^2=c(resultant )
10.56+22.56=33.12
square root of 33.12 is 5.75
A boiling liquid absorbs thermal energy (heat) at a rate of 450 W. The specific latent heat of vaporisation is 2.7 × 106 J / kg
Explanation:
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A man attached a rope to a 30 kg box of books. He pulls with a force of 120 N at an angle of 60 with the horizontal. The kinetic friction is 33 N. Find the net force acting on the box.
Answer:
[tex]F_{net}=27N[/tex]
Explanation:
The forces acting on the box are:
The x-component of the pulling force [tex]F_{x}[/tex] and the friction force [tex]F_{fr}[/tex]. We assume positive in the direction of the pulling force in the x-component.
[tex]F_{net}=F_{x}-F_{fr}[/tex]
[tex]F_{net}=Fcos(60)-F_{fr}[/tex]
[tex]F_{net}=120cos(60)-33[/tex]
[tex]F_{net}=27N[/tex]
I hope it helps you!
A box has a momentum of 38.0 kg*m/s to the right. A 88.3 N force pushes it to the right for 0.338 s. What is the final momentum of the box? (unit = kg*m/s)
Answer:
63.8454kgm/s
Explanation:
According to Newton's second law;
Force = mass ×acceleration
Fore = m(v-u)/t
Force = mv-mu/t
MV is the final momentum
mu is the initial momentum = 38kgm/s
Force = 88.3N
Time = 0.338s
Substitute and get mv
88.3 = mv-38/0.338
88.3×0.338 = mv-38
29.8454 = mv-38
MV = 29.8454+34
mv = 63.8454kgm/s
Hence the final momentum is 63.8454kgm/s
Answer:
67.8
Explanation:
im an acellus student, and this is the answer that i got when doing the problem.
3 QUESTIONS (SCIENCE)
First question: What can bad space weather do to earth?
Second question: What is the purpose of the United Nations Committee, and what do they do?
Third question: What protect Earth form much of the damage from space weather?
1. Explain why a piece of white paper looks green when viewed through a piece of green plastic?
Answer:
because the light is refracted and slowed down to make us see the color "green" and the things we see..like paper..the color "green" A white sheet of paper reflects almost all the light that falls on it. It reflects white light because it can reflect all the colors of the spectrum that comprise white light. If red light only is shone onto a white page, the red light is reflected. If the green light is shone onto the page, the green light is reflected.
Explanation:
hope this helps?
Answer:
the wave length that are reflected determine the color that an object appears to the human eye. for example,the leaves appear green because they reflect green light and absorb light of other wavelengths.This means that the light passes through the material rather than being reflected by it.
Explanation:
I’m bored please end my boredom
Answer:
Watch something educational
Explanation:
Like Anime
There are several things you can do to end your boredom time like you can watch movies, you can read books, or can go trekking or something.
What is boredom?According to conventional definitions, boredom is a sentimental and sporadically psychological state that occurs when someone is left without something specific to do when they feel listless and dissatisfied due to a lack of activity or excitement, when they are uninterested in one’s surroundings, or when they think a day or period is tedious.
Scholars also view it as a contemporary phenomenon with a cultural component. There is no agreed-upon definition of boredom.
There are several ways to tackle with boredom:
Call your best friend.Make a dish for yourselfTry out a new hobby.You can join a new clubExercise according to your preferred routine, or start something different, like a dance class.To know more about boredom:
https://brainly.com/question/27962717
#SPJ2
A surface has the area vector A = (10i + 8j) m2. Find the flux of a uniform electric field through the area if the field is E = 7i N/C
Answer:
The value is [tex]\phi = 70 N\dot m^2 / C[/tex]
Explanation:
From the question we are told that
The area vector is [tex]\vec A = (10i + 8j) \ m^2[/tex]
The electric field is [tex]E = 7 i \ N/C[/tex]
Generally the flux is mathematically represented as
[tex]\phi = \vec E * \vec A[/tex]
=> [tex]\phi = 7i * ( 10 \ i + 8 \ j )[/tex]
=> [tex]\phi = (7 * 10 )\ i[/tex]
Note [tex]i \cdot j = 0[/tex]
=> [tex]\phi = 70 N\dot m^2 / C[/tex]
a group of interacting parts that move or work together
Answer:
A system is a group of interrelated interacting, or interdependent parts that for a complex whole. A system is a group of interrelated interacting, or interdependent parts that for a complex whole.
Explanation: Hope this helps ;)
All of the following are types of models EXCEPT
O a theory.
Dan analogy.
Oa physical replica.
O a mathematical representation.
Answer:
A theory
Explanation:
No, the person who answered above is incorrect. I just took the assessment and I can guarantee you the answer is "a theory".
-Lexi
Determine the velocity of a wave with frequency 10Hz and a wavelength of 10m.
Answer:
A wave with a frequency of 10 Hz and a wavelength of 10 m should have a velocity of 100 meters per second (m/s)
Explanation:
True of False, in physics the term weight and force of gravity have the
same meaning?"
Help with both questions please.
Answer:
1) True
2) None of the above
Explanation:
Q # 1:
Weight is actually the gravitational force or force of gravity. So, it's true.
Q # 2:
None of above because force of gravity can not be negative. In order to have a negative weight, the body has to be "repelled" by gravity.
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!
~AH1807Why do humans to experience the four seasons
Answer:
As the earth spins on its axis, producing night and day, it also moves about the sun in an elliptical (elongated circle) orbit that requires about 365 1/4 days to complete. The earth's spin axis is tilted with respect to its orbital plane. This is what causes the seasons.
Explanation:
a beach ball is left in the bed of a pickup truck. Describe what happens to the ball when the truck accelerates forward
A student kicks a ball of 1 kg with a velocity of 13ms. The contact is 0.2 sec. Find the force
Answer:
65 N
Explanation:
Assuming that the ball was at rest hence initial momentum = 0
Final momentum = mv = 1Kg × 13 ms-1 = 13 kgms-1
But
Ft= mv according to Newton's law
F= mv/t
F= 13kgms-1/0.2s
F= 65 N
Answer:
65 N
Explanation:
Given that :
Mass of ball = 1kg
Velocity = 13m/s
Time = 2 seconds
Using the relation :
Force = (mass * change in velocity) / time
The change in momentum of the ball :
Momentum = mass * change in velocity
Velocity change = (13 - 0) ; Given that initial velocity = 0 (at rest)
Momentum = 1kg * 13m/s
Momentum = 13 kgm/s
Therefore, the force, F equals;
F = change in momentum / time
F = 13kgm/s ÷ 0.2 s
Hence, Force, F = 65N
20 n west and 60 n east
BLANK 1: What is the net force acting on the object
BLANK 2: Which direction will the object move
Answer:
a) [tex] F_{T} = 40 N [/tex]
b) The object will move in the east direction
Explanation:
a) The net force is given by the vector sum of the given forces:
[tex] F_{T} = F_{1} + F_{2} [/tex]
Where:
F₁ = the west force = 20 N
F₂ = the est force = 60 N
Taking the east direction as the positive direction we have:
[tex] F_{T} = -20 N + 60 N = 40 N [/tex]
Hence, the net force is 40 N.
b) Since the east force is greater than the west force, the object will move to the east.
I hope it helps you!
El motor de una licuadora gira a 3600 rpm, disminuye su velocidad angular hasta 2000 rpm realizando 120 vueltas. Calcular: a) La aceleración angular b) El tiempo transcurrido
Answer:
a) α = -65,2 rad/s².
b) t = 2,57 s.
Explanation:
a) La aceleración angular se puede calcular usando la siguiente ecuación:
[tex] \omega_{f}^{2} = \omega_{0}^{2} + 2\alpha \theta [/tex]
En donde:
[tex]\omega_{f}[/tex]: es la velocidad angular final = 2000 rpm = 209,4 rad/s
[tex]\omega_{0}[/tex]: es la velocidad angular inicial = 3600 rpm = 377,0 rad/s
α: es la aceleración angular=?
θ: es el desplazamiento o número de vueltas = 120 rev = 754,0 rad
Las conversiones de unidades se hicieron sabiendo que 1 revolución = 2π radianes y que 1 minuto = 60 segundos.
Resolviendo la ecuación (1) para α, tenemos:
[tex]\alpha = \frac{\omega_{f}^{2} - \omega_{0}^{2}}{2\theta} = \frac{(209,4 rad/s)^{2} - (377,0 rad/s)^{2}}{2*754,0 rad} = -65,2 rad/s^{2}[/tex]
Entonces, la aceleración angular es -65,2 rad/s². El signo negativo se debe a que el motor está desacelerando.
b) El tiempo transcurrido se puede encontrar como sigue:
[tex] \omega_{f} = \omega_{0} + \alpha t [/tex]
Resolviendo para t, tenemos:
[tex]t = \frac{\omega_{f} - \omega_{0}}{\alpha} = \frac{209,4 rad/s - 377,0 rad/s}{-65,3 rad/s^{2}} = 2,57 s[/tex]
Por lo tanto, el tiempo transcurrido fue 2,57 s.
Espero que te sea de utilidad!
What does the slope on a velocity-time graph measure?
Answer:The slope in the velocity-time graph represents the acceleration. The slope is defined as the ratio of change in y-axis to change in the x-axis. The slope is represented by the letter m and following is the general formula used for determining the slope:
Explanation:
Calculate the pressure in pascals if a 650N force is applied to an area of 6.5m².
Answer:
100 Pa
Explanation:
650 ÷ 6.5 = 100 ( Pa )
[tex]\\ \sf\longmapsto Pressure=\dfrac{Force}{Area}[/tex]
[tex]\\ \sf\longmapsto Pressure=\dfrac{650}{6.5}[/tex]
[tex]\\ \sf\longmapsto Pressure=100Pa[/tex]
PLEASE HELP ASAP!!!
Bradley is installing fencing on a farm. As he is installing the fencing, he moves 65.0 meters directly south, then turns, and goes 44.0 meters at an angle 25.0° east of south, where he finishes his work shift. What is his final displacement vector at the end of his shift??
a. 107m, 10.1°, east of south
b. 107m, 10.1° south of east
c. 121m, 14.1° south of east
d. 121m, 14.1° east of south
Answer:
The correct option is;
a. 107 m, 10.1°, east of south
Explanation:
The given question can be answered using vectors as follows;
The initial displacement south by Bradley = 65.0 meters
In vector form, we have
The initial displacement south by Bradley = -65·j
The displacement 25.0° east of south = 44.0 meters
In vector form, we have
The displacement 25.0° east of south = 44 × sin(25°)·i - 44 × cos(25°)·j
In vector, form, we have;
The total displacement = The sum of the vectors of the two displacement
∴ The total displacement = -65·j + 44 × sin(25°)·i - 44 × cos(25°)·j
The total displacement = 44 × sin(25°)·i - (44 × cos(25°) + 65)·j
We use the i and j components to find the magnitude and the direction of the total displacement as follows;
The magnitude of the total displacement = √((44 × sin(25°))² + (44 × cos(25°) + 65)²) = 106.5132881 ≈ 107
The magnitude of the total displacement ≈ 107 m
The direction of the total displacement = arctan((44 × sin(25°))/((44 × cos(25°) + 65)) = 10.0542797419° ≈ 10.1° east of south
A car is traveling at an average speed of 120km/h.how long will it take to travel between two station 525km apart?
Answer:
Time taken 4 hrs. 38 minutes
Explanation:
As speed = distance/time interval
So time taken = 4.38
speed=distance/time
we know the speed and we know the distance so we can calculate the time
120km/h=525km/time
time=525km/120km/h=4.375hours or 4 hours and 22 minutes and 30 seconds