What is concave mirror?
Answer:
A concave mirror, or converging mirror, has a reflecting surface that is recessed inward (away from the incident light). Concave mirrors reflect light inward to one focal point. They are used to focus light.
if A vector = i^-j^+k^ then unit vector in the direction of A vector
a)√3,j^
b)(i^-j^+k^)
c)(i^-j^-k^)/√2
d)(i^-j^+k^)/√3
plzz answer my question with explanation
If A = i - j + k, then the magnitude of A is
||A|| = √(1² + (-1)² + 1²) = √3
Then the unit vector in the direction of A is 1/||A|| multiplied by A :
u = A/||A|| = (i - j + k)/√3
(choice D)
what is the difference between MKS system and SI system of measurement
Answer:
The MKS (metre, kilogram, second) system of units is the fundamental core of the SI (Systeme Internationale, or International System) of measurement. As various fields grow new forms of measurements based on MKS, terms or exact definitions may vary in different scientific or engineering disciplines. These inconsistencies are sorted out by the international committee that defines the SI system of units and keeps it up to date.
So the MKS is the static core, and the SI is the evolving, growing system of metric measurement.
Metres and kilograms were introduced after the French Revolution around 1790. Seconds were added by the 1830s, building the MKS system. More units came later. By 1948, a need was seen to develop a clear and consistent set of terms for measurement, and this led to 12 years of work, ending with the release of the first version of the SI in 1960.
The SI now has seven base units of measure. It begins with the original three metre, kilogram, and second, and adds the ampere for electricity, candela for light, kelvin for temperature, and mole for amount (number of atoms or molecules) of a substance.
The SI defines how each fundamental unit can be measured or obtained experimentally. These definitions have changed over time. For example, the metre was originally a measure related to the circumference of the Earth, then a set number of waves of a particular wavelength, and now a distance traveled by light in a vacuum in a certain period of time.
The SI also defines modifying terms such as milli-, centi-, and kilo- that are a specific number of each unit.
The SI includes many other derived units, as well.
By standardizing international use of measurements across different fields of science and engineering, the SI reduces confusion that would slow scientific progress and error that can produce engineering catastrophe such as the loss of the Mars Climate Orbiter in 1999 due to a table that should have been in metric units (kilograms and meters) being provided in United States customary units (pounds and inches).*
The Mars Climate Orbiter and its mission were lost due to a failure to use SI units consistently.
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A car is moving with the velocity of 90km/h. If the car come to rest after 10 seconds. Calculate the final velocity and distance covered by the car within that time.
plz wirte the full formula
Answer:
you can learn from here
https://www.toppr.com/ask/en-bd/question/a-car-is-moving-with-a-velocity-of-10-ms-the-driver-sees-a-wall/
DOES STONE DISPLACE MORE WATER THAN ITS WEIGHT
A coin is placed at a depth of 15 cm in a beaker from the surface of water. Therefractive index of water is 4/3.Calculate height through which the image of the coin is raised.
I found this answer on another website.
direct or indirect
"Susan is a lovely ten-year-old girl from Hawaii."
Answer:
Direct
Explanation:
which species are near extinctions and where do they live now?
Answer:
Amur Leopard, Southeastern Russia, and northern china
Explanation:
Answer:
Amur Leopard China/Russia
Hawks bill Turtle live in Oceans
if a girl is running along a straight road with uniform velocity 1.5 metre per second find the acceleration
Answer:
Acceleration is 0.
Explanation:
Since the girl is running with a uniform velocity, meaning she is moving at a constant rate, she is not accelerating. Acceleration only occurs when the speed of an object increases, decreases, or if there is a change in direction.
explain radiation and which is the hotest source in the world
Ramsar has the highest level of natural radiation in the world.
Hot springs located in the Arkaroola Wilderness Sanctuary in Southern Australia are also credited with higher than normal radiation levels, due to spring water coming in contact with rocks rich in uranium and radon.
How does the comets energy change as it moves from point a to point d
Answer:
At point A, the comet has the least kinetic energy because the comet is resting. 3. From point B to point D its orbit's potential energy is decreasing and its kinetic energy is increasing meaning it's moving more and more
Name of compounds
a. H2Co3
b. NH4OH
c.AlPO4
d.NaOH
e.AuCI3
Answer:
a) Carbonic acid
b) ammonium hydroxide
c) Aluminum phosphate
d) Sodium hydroxide
e) Gold trichloride
Explanation:
I hope this will help you buddy
What did Ernest Rutherford's experiment of a beam of alpha particles aimed
at a sheet of gold foil lead him to conclude?
A. The theory that atoms were the building block of all matter was
correct.
B. The majority of the atom's mass and its positive charge are
concentrated in the atom's center.
C. An electron has a larger mass than the alpha particles, causing
them to reflect upon collision.
D. J.J. Thomson's theory of electrons suspended in a sea of
positively charged particles was correct.
Answer:
B - Only a concentration of mass in the nucleus could explain the deflection of the incident particles.
A block of amber is placed in water and a laser beam travels from the water through the amber. The angle of incidence is 35 degrees while the angle of refraction is 24 degrees. What is the index of refraction of amber?
(index of refraction of water is 1.33)
If the power of a working system(machine) is 2088.8 watts then its power in horsepower will be: A. 1hp B. 2.7hp C. 2.9hp D. 2.8hp
Answer:
D. 2.8 hp
Explanation:
1 hp=746 watts
2088.8÷746= 2.8
6. A car moving in a straight line at constant speed:
A. is accelerating.
B. is decelerating.
C. must be on a downhill slope.
D. has no overall force acting on it.
Answer:
D. has no overall force acting on it.
Explanation:
Why?
Because in a straight line at the constant speed means the car moving in the same velocity, which is not acceleration neither deceleration, and it cannot be on a downhill slope. So the correct answer is
→ D. has no overall force acting on it.Calculate the relative atomic mass of MgO
Answer:
MgO relative atomic mass is 40
Explanation:
Mg=24
O=16
Why aren’t magazine photos a good representation of what a healthy person looks like
You observe that you see more mockingbirds in small trees and more hawks in large trees. Which of the following is an appropriate scientific question based on this observation?
How does the size of a tree affect the bird species that prefer to live in it?
How do birds fly?
What type of food do birds eat?
What time of year to birds mate?
Answer:
A) How the size of a tree affect the bird species that prefer to live in it
Explanation:
I took the quiz
The mass of earth 6*10^24kg its radius is 6.4*10^3km now calculate due to gravity on earth
Answer:
Explanation:
in your textbook, they have a formula like this:
g=mass of earth*G/R^2
G=6.67*10^-11
apply to this
we have g=6*10^2*4*6.67*10^-11/(6.4*10^3*1000)^2=9.78
Please please helpjejejnebwbww
Answer:
C. 540 N
Explanation:
Let suppose that system formed by the athlete and the load are in equilibrium. By Newton's Laws of Motion, we use the moment equation with respect to the feet of the athlete to determine the upward force exerted by his two arms:
[tex]\Sigma M = -F\cdot r_{1} + m_{L}\cdot g \cdot r_{2} + m_{A}\cdot g \cdot r_{3} = 0[/tex]
[tex]F = \frac{(m_{L}\cdot r_{2} + m_{A}\cdot r_{3})\cdot g}{r_{1}}[/tex] (1)
Where:
[tex]m_{L}[/tex] - Mass of the load, in kilograms.
[tex]m_{A}[/tex] - Mass of the athlete, in kilograms.
[tex]g[/tex] - Gravitational acceleration, in meters per square second.
[tex]r_{1}[/tex], [tex]r_{2}[/tex], [tex]r_{3}[/tex] - Distances with respect to the feet, in meters.
[tex]F[/tex] - Upward force exerted by his two arms, in newtons.
If [tex]m_{L} = 6\,kg[/tex], [tex]r_{2} = 1.20\,m[/tex], [tex]m_{A} = 70\,kg[/tex], [tex]r_{3} = 0.90\,m[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]r_{1} = 1.30\,m[/tex], then the upward force is:
[tex]F = \frac{[(6\,kg)\cdot (1.20\,m)+(70\,kg)\cdot (0.90\,m)]\cdot \left(9.807\,\frac{m}{s^{2}} \right)}{1.30\,m}[/tex]
[tex]F = 529.578\,N[/tex]
The upward force exerted by his two arms is 529.578 newtons. (Right answer: C)
Ella is blowing up balloons in preparation for her sister's birthday. Ella finds some balloons hanging outside the house explode after a few hours. Explain why.
Answer:
they were in the sun for long
A man pulls his luggage on a 30 degree incline with a constant force of 25 N. How
much work does he do after walking 20.0 m?
a) 430 J
b) 330J
c) 1500J
d) 250 J
We know
[tex]\boxed{\sf W=Fscos\theta}[/tex]
[tex]\\ \sf\longmapsto W=25(20)cos30°[/tex]
[tex]\\ \sf\longmapsto W=500\times \dfrac{\sqrt{3}}{2}[/tex]
[tex]\\ \sf\longmapsto W=250\sqrt{3}[/tex]
[tex]\\ \sf\longmapsto W=250(1.73)[/tex]
[tex]\\ \sf\longmapsto W\approx 430J[/tex]
Option a) 430 J work done he do after walking 20.0 m.
What is work?Work, in physics, is a measure of energy transfer that happens when an object exists moved over a distance by an external force at least part of which exists involved in the direction of the displacement.
Displacement exists as the distance moved in a straight line, in a provided direction, from the starting point. Displacement exists as a vector quantity as it includes size and direction.
An angle stands the figure formed by two rays, named the sides of the angle, sharing a standard endpoint, named the vertex of the angle.
Force=F=25NDisplacement=s=20mAngle=30°⇒[tex]W=Fcos\theta[/tex]
⇒[tex]W=25(20)cos 30^{0}[/tex]
Then,
⇒[tex]W=50*\sqrt{3} /2[/tex]
⇒[tex]W=250\sqrt{3}[/tex]
Hence,
⇒[tex]W=250(1.73)[/tex]
[tex]W[/tex] approximately 430J.
Hence, Option a) 430 J work done he do after walking 20.0 m.
To learn more about Displacement refer to:
https://brainly.com/question/321442
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(a) What kind of energy is possessed by an aeroplane flying at a height of 10000 m?
Answer:
When the plane is rest position it possess potential energy. But when a aeroplane is flying at the height it possess kinetic energy. No matter what height is given.
f an object has a mass of 200 kg and a weight of 1000 N, what is g?
Answer:
g = 5 m/s square
Explanation:
Weight(W), Mass(m), Gravity(g)
W = mg
1,000N = 200g
g = 1000/200
g = 5 m/s square
high priority should be given for the development and use oc hydroelectricity justify with reason
Answer:
because hydroelectricity is generate from water and it is considered as a perpetual resources and produce the large capacity of electricity which helps in the indicator of development
ASAP!! Please help me out here
Answer:
Option: DExplanation:
As,
In Option,
A:
There are two same positive ions so they will move away from each other.
B:
There is one negative and positive ion so they will move towards each other.
C:
Again there is one negative and positive ion so they will move towards each other.
D:
Here, there is neutral ions so they will not move and its the correct option.
Global warming is threatening polar bear habitats and the bears' way of life. If trends continue, predict what will become of the polar bear in the next 10,000 years. Will it adapt or become extinct? Defend your answer.
Bear will become extinct due to global warming.
What is greenhouse gas?The gases which get easily trapped inside the glasses and increase the temperature of the atmosphere causing the global warming level to increase overall.
Global warming is threatening polar bear habitats and the bears way of life. If global warming continues, predict what will become of the polar bear in the next 10,000 years
Thus, bear will extinct.
Learn more about greenhouse gas.
https://brainly.com/question/4509458
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An object has a kinetic energy of 8.8J and a mass of 450g. How fast is the object moving?
Answer:
Explanation:
The formula for KE is
[tex]KE=\frac{1}{2}mv^2[/tex] We have everything we need to solve for the velocity, but we first have to convert the mass from grams to kg:
450 g = .450 kg
[tex]8.8=\frac{1}{2}(.450)v^2[/tex] and we'll rearrange that and solve it for v before we do any math:
[tex]v=\sqrt{\frac{2(8.8)}{.450} }[/tex] so
v = 6.3 m/s rounded to the correct number of sig fig's
how many significant figures 216 m
Answer:
Three
Explanation:
I hope this helps:)
