The diameter of the reflecting surface of spherical mirror is called its aperture. Mirrors whose aperture is much smaller than its radius of curvature, we use R=2f.
When a beam of light is incident on a surface, it delivers energy to the surface. The intensity of the beam is defined as the energy delivered per unit area per unit time.
What is the unit of intensity, expressed in SI base units?
Answer:
Kg
Explanation:
Given that the definition of intensity is:
The intensity of the beam is defined as the energy delivered per unit area per unit time. That is,
I =( E × t)/A
Which can expressed as
I = J/m^2/s
The S.I Units of
Energy is Joule = kgm^2s^-1
Area A = m^2
Time t = s
Intensity I = kgm^2s^-1 × m^-2 × s
Intensity I = kg
The cubic metres and seconds are cancelled out
Therefore, the S.I units of intensity is kg
water in a cup and a kettle can have the same temperature even though the quantities are different . give reasons
Answer:
The reason is because both are exposed to a virtually infinite heat sink, due to the virtually infinite mass and of the surrounding environment, compared to the sizes of either the cup or the kettle such that the equilibrium temperature, [tex]T_{(equilibrium)}[/tex] reached is the same for both the cup and the kettle as given by the relation;
[tex]\infty M_{(environ)} \times c_{(environ)} \times (T_2 - T_1) = m_{1} \times c_{(water)} \times (T_3 - T_2) + m_{2} \times c_{(water)} \times (T_4 - T_2)[/tex]
Due to the large heat sink, T₂ - T₁ ≈ 0 such that the temperature of the kettle and that of the cup will both cool to the temperature of the environment
Explanation:
What is the acceleration of a car that slows down from 25.0 m/s to 10.0 m/s in 30 seconds? The car is traveling south.
Astronauts who traveled to the moon were able to float slightly as they walked along its surface. Why were the astronauts able to do this? The weight of the astronaut on Earth is less than his weight on the moon. The mass of the astronaut on Earth is less than his mass on the moon. The weight of the astronaut on Earth is greater than his weight on the moon. The mass of the astronaut on Earth is greater than his mass on the moon.
Answer: The weight of the astronaut on earth is greater than his weight on the moon.
Explanation:
The reason I got this answer is because the astronaut will have the same mass on the moon as he does on earth. Also the weight of a person or object is determined by gravity. So since the moons gravity isn’t as strong as earths gravity the astronauts are lighter in terms of weight, and this is how they slightly float.
The weight of the astronaut on Earth is greater than his weight on the Moon. The third option is correct.
What is gravity?The force of attraction felt by a person at the center of a planet or Earth is called as the gravity.
The Earth has the acceleration due to gravity, g = 9.81 m/s², Moon has the acceleration due to gravity 6 times less than that of Earth.
Astronauts who traveled to the Moon were able to float slightly as they walked along its surface. The astronauts were able to do this because they have the same mass on the Moon as he does on Earth.
The weight of a person or object is determined by gravity. Since, the Moon's gravity isn’t as strong as Earth's gravity. So, the astronauts slightly float on Moon.
The weight of the astronaut on Earth is greater than his weight on the moon.
Thus, the third option is correct.
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Marcus is on a train that travels 20 and takes 5 seconds to slow to 10 .
How would Marcus correctly calculate the acceleration?
Answer:
-2
Explanation:
v0=20
v=10
t=5
a=(v-v0)/t=(10-20)/5=-2
an object accelerates from rest to a speed of 24m/s over a distance of 56 m. what acceleration did it experience
The distance time graph of a body is a straight line parallel to the time axis. What
information does the graph convey regarding the motion of the object?
Explanation:
The object is not moving, because the distance is a constant value regardless of the time value.
Alan rents a private jet for the weekend. He flies 400km south to New York then flies 821km south to North Carolina, then 1200km to Miami. What distance did he cover ? What was his displacement ?
Answer:
Distance = 2421 km
Displacement I'm not sure
I live in Asia
Which is always true in a closed system?
Acceleration is not constant.
Mass is not conserved.
Momentum is conserved.
Velocity is constant.
Answer:
The correct option is momentum is conserved
Explanation:
A closed system is a system that is independent/free of external factors/force and does not exchange matter with its surrounding. Since a close system is free of external factors/force; acceleration is constant in it, mass is conserved in it and there will be changes in velocities of objects in the closed system.
This question actually seeks to test our knowledge of the law of momentum. The law of conservation of momentum states that the momentum of a closed system is conserved.
C: Momentum is consevered
The flow of air from land to a body of water is called a _______________________.
When The north end of earths axis is tilted toward the sun, what will North America experience? Choices, 1. More indirect rays and shorter days 2. More indirect rays and longer days 3. more direct rays and shorter days 4. more direct rays and longer days
Answer:
day 4
Explanation:
it more direct rays nd it's longer days
When removing heavy objects that may change the center of gravity of a vehicle ________. Group of answer choices
Answer:
______________________________
use tall safety and position hoist arms
A uniform beam weighing 1 N is used as a metre rule. The beam is supported by a pivot
at the 30 cm mark. A 12 N weight is hung at the 0 cm mark and a 2 N weight is hung at the
60 cm mark as shown in Figure 5.19.
O cm
50 cm 60 cm
100 cm
수
► Figure 5.19
30 cm
mark 1 N
12 N
2 N
W
What is the weight W of a mass hung at the 100 cm mark in order to balance the beam?
Please help!
Answer:
then you solve two torque one is anticlockwise and one is clock wise toque 1=force*perpendicular distance is equal to torque 2= force* perpendicular distance so tau = torque 1+ torque 2and give your answer
Answer:
W = 4 N (to balance the beam)
Explanation:
take moment at support Δ
∑M at Δ = 0 (note: clockwise is + and counter clockwise is - )
0 = W(100 - 30) + 2(60-30) + 1(50-30) - 12(30)
0 = W70 + 2(30) + 1(20) - 360
0 = W70 + 60 + 20 - 360
0 = W70 - 280
280 = W70
W = 280 / 70
W = 4 N (to balance the beam)
to take the reaction at support Δ
Δ = 12 + 1 + 2 + 4
Δ = 19 N
proof that W = 4
∑M at 12N = 0
0 = 19(30) - 1(50) - 2(60) - W(100)
0 = 570 - 50 - 120 - 100W
100W = 400
W = 400 / 100
W = 4 N -------- ok
A person can be _____ to disease due to long-term malnutrition
Answer:
Abnormal or excessive fat accumulation
Explanation:
Malnutrition refers to getting too little or too much of certain nutrients. It can lead to serious health issues, including stunted growth, eye problems, diabetes and heart disease. Malnutrition affects billions of people worldwide
If several negative charges surround a large positive charge, the total force on a far away charge is reduced. What is this effect called
Answer:
this effect is called SCREENING
Explanation:
When a positive charge is surrounded by several negative charges at a long distance, an apparent decrease in the positive charge is observed, this effect is called SCREENING and is noticeable in multielectronic atoms
This effect is responsible for the decrease in ionization energy in the larger atoms.
How many atoms of each element Are in the chemical formula NH4 NO3
Answer:
NITROGEN - 2
HYDROGEN- 4
OXYGEN- 3
Which statement describes an energy measurement?
There are no statements provided for my me to choose from, but i'll try.
Here's what I've got for ya:
1 Joule (J) is the MKS unit of energy, equal to the force of one Newton acting through one meter. 1 Watt is the power from a current of 1 Ampere flowing through 1 Volt. 1 kilowatt is a thousand Watts. 1 kilowatt-hour is the energy of one kilowatt power flowing for one hour.
Prob. not that helpful, sorry, but I can't read your mind to understand what the statements were, sorry.
Hope this is at least kinda helpful!
PLZ HELP TIMED TEST
Which would be most useful for overcoming the disadvantage of using ores?
using public transportation
recycling aluminum products
buying paper instead of plastic
minimizing electricity usage
Answer:
recycling aluminum products
Explanation:
I I took this test hope this out and on the test I got this correct
An organism ingests a toxin that damages the mitochondria of its cells.
Which function of the mitochondria might be inhibited in the cell?
Choose 1 answer:
(Choice A) A Producing sugar from sunlight
(Choice B) B Converting energy stored in sugar to ATP
(Choice C) C Creating proteins
(Choice D) D Disposing of damaged cell parts
 Match the vocabulary word to its definition
Answer:
PROTON - A positively charged particle located in the nucleus of an atom./ ELECTON CLOUD - The area of the atom surrounding the nucleus where electrons can be found. / ELECTRON - A negatively charged particle that orbits the nucleus of an atom. / NUCLEUS - The central part of the atom containing protons and neutrons. / NEUTRON - A neutral particle located in the nucleus of an atom.
Explanation:
The answers are:
PROTON - A positively charged particle located in the nucleus of an atom.ELECTRON CLOUD - The area of the atom surrounding the nucleus where electrons can be found.ELECTRON - A negatively charged particle that orbits the nucleus of an atom.NUCLEUS - The central part of the atom contains protons and neutrons. NEUTRON - A neutral particle located in the nucleus of an atom.What is a nucleus in the atom?The nucleus is a positively charged region at the center of the atom. It consists of two types of subatomic particles packed tightly together. The particles are protons, which have a positive electric charge, and neutrons, which are neutral in electric charge.
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A torn T-shirt was found in the back seat of a suspect's car. Two pieces of torn cloth were found at the scene of the crime. Can the two pieces be individualized to the T-shirt? Explain.
Answer:
Yes you can
Explanation:
Match the tears found on the individual pieces with the individual holes seen on the shirt
prove that Force is equal to mass and acceleration
What is the following correct way to write 2,330,000 in scientific notation
Answer:
The answer is 2.33 × 10 race to 6.
A load of 800 N is lifted using a block and tackle having 5 pulleys. If the applied effort is 200 N, calculate
i. Mechanical advantage
ii. Velocity ratio
iii. Efficiency
iv. Output work if load is lifted 5m high.
v. Input work
Explanation:
Load=800N
Effort=200N
1. Mechanical Advantage = LOAD/EFFORT
= 800N/200N
= 4
2 Velocity Ratio = no. Of pulleys =5
3. Efficiency = Mechanical advantage / velocity ratio × 100%
= (4/5)×100%
=80%
4. output work= load×load distance
= 800N × 5m
= 4 × 1000J
5. Efficiency = (output work/input work) ×100%
Or, 80% = (4000J/input work) ×100%
Or, 80%/100% = 4000J/inputwork
Or, 4/5 = 4000J/inputwork
Or, input work =4000J × 5/4
Input work = 5×1000J
I hope it helped! ;-)
Answer:
I got the same answers.
Explanation:
I agree with the first person respone.
A person walk 12.0m east , then turns and goes 8.00 m west , then turns and goes back 2.00m east. What is the person’s displacement and distance?
Answer:
Distance = 22m
Displacement = 12 + 2 - 8 =6m
What is the momentum of a 3 Kg ball that is traveling at 9 m/s to the left?
Answer:
Explanation:
momentum =mv
p=mv
given mass=m= 3 kg
given velocity=v=9 m/s
therefore p is
p=mv
p=3*9
p=27 kgm/s
Which of following answer choices properly match the cell structure and function depicted by this image?
Choose 1 answer:
(Choice A)
A
Nucleus — storage of genetic material
(Choice B)
B
Golgi body — receiving, sorting, and packaging cell materials for transport
(Choice C)
C
Golgi body — breaking down sugar molecules and converting their energy to ATP for the cell
(Choice D)
D
Lysosome — receiving, sorting, and packaging cell materials for transport
Answer:
B
Golgi body — receiving, sorting, and packaging cell materials for transport
Explanation:
The Golgi body is responsible for receiving, classifying, and packing cell components for transportation in a manner that is consistent with the cell form and function are shown in this figure. Option B is correct.
What are Golgi bodies?The majority of eukaryotic cells' cytoplasm contains a combination of vesicles and folded membranes that are used for secretion and intracellular transport known as the Golgi bodies.
Golgi body — receiving, sorting, and packaging cell materials for transport properly match the cell structure and function depicted by this image.
This graphic accurately depicts the cell structure and function of the Golgi body, which receives, sorts, and packages cell components for transit.
Hence, option B is correct.
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Chich expression correctly describes force using Sl units
O A. 1 N = 1 kg-m/s2
B. 1 N = 1 kg.m/s
C. 1 J = 1 kg-m/s?
D. 1 J = 1 kg m/s
Answer:1 N = 1 kg·m/s2
Explanation:
Extrinsic statements originate in a. Parents c. Teachers b. Society d. All of these Please select the best answer from the choices provided A B C D
Answer:
D all of these
Explanation:
Extrinsic statements originate in parents ,society and teachers. Option D is correct.
What is extrinsic motivation ?Extrinsic motivation is defined as conduct motivated by external incentives. Extrinsically driven people will continue to do something even if it isn't pleasurable or rewarding in and of itself.
These incentives might be monetary or intangible in nature, such as acclaim or renown. Extrinsic motivation is distinct from intrinsic motivation in that it is only motivated by external incentives.
Extrinsic statements originate in;
a. Parents
b. Society
c. Teachers.
Extrinsic statements originate in all of the above given option.
Hence, option D is correct.
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If the toy helicopter weighs 115 N and is hovering motionless in the air, which of these options MOST accurately describes the force that the helicopter's propeller must exert?
Answer:
If the helicopter is not moving, then it is not being accelerated.
By second Newton's law we have that:
F = m*a
Force equals mass times acceleration.
Then if we do not have acceleration, we have:
F = m*a = m*0 = 0.
Then the total force must be zero.
So if the gravitational force (pulling down) is 115N, then the force of the propeller must be such that:
Total force = F - 115N = 0
F = 115N
The force of the propeller must be also of 115N, but in the opposite direction.