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When light strikes a black surface, it is reflected by the surface and
nothing is absorbed This would be False because black absorbs the light not reflect
Mirrors are used in telescopes because they have the ability to reflect
True? Telescopes designed with mirrors avoid the problems of refracting telescopes. Because the light is reflected from the front surface only, flaws and bubbles within the glass do not affect the path of the light
Transmission in the passing of light through some materials
False? Some materials allow much of the light that falls on them to be transmitted through the material without being reflected. Materials that allow the transmission of light waves through them are called optically transparent. ... Materials which do not allow the transmission of any light wave frequencies are called opaque.
A parallel plate capacitor of capacitance Co has plates of area A with separation d between them. When it is connected to a battery of voltage Vo, it has charge of magnitude Qo on its plates. It is then disconnected from the battery and the plates are pulled apart to a separation 2d without discharging them. After the plates are 2d apart, the new capacitance and the potential difference between the plates are: (Show all steps) [2 marks] a. ½ Co, ½ Vo b. ½ Co, 2Vo c. Co, Vo d. Co, 2Vo e. 2Co, 2Vo
Answer:
b. 1/2·C₀, 2·V₀
Explanation:
The capacitance on the parallel plate capacitor = C₀
The area of the plates = A
The voltage on the battery = V₀
The magnitude of the charge on the plate = Q₀
The new distance between the plates = 2·d
From an online physics source, we have;
[tex]C_0 = \epsilon_0 \times \dfrac{A}{d}[/tex]
Where;
ε₀ = Constant
A = The area of the plates
With the new distance, 2·d, we get;
[tex]C_{new} = \epsilon_0 \times \dfrac{A}{2\cdot d} = \dfrac{1}{2} \times \epsilon_0 \times \dfrac{A}{d} = \dfrac{1}{2} \times C_0[/tex]
Therefore;
[tex]The \ new \ capacitance \ C_{new} = \dfrac{1}{2} \times C_0[/tex]
The potential difference, 'V', is given as follows;
[tex]C = \dfrac{Q}{V}[/tex]
Therefore;
[tex]V = \dfrac{Q}{C}[/tex]
Given that Q = Q₀, we get;
[tex]V = \dfrac{Q_0}{\dfrac{1}{2} \times C_0} = 2 \times \dfrac{Q_0}{C_0} = 2 \times V_0[/tex]
∴ V = 2 × V₀
The new potential difference, V = 2·V₀
Therefore, after the plates are 2·d apart, the new capacitance and potential difference between the plates are;
1/2·C₀, 2·V₀.
At a distance of 2d, the potential difference will be twice the potential difference before while the capacitance will be half the value before.
Given to us
The capacitance on the parallel plate capacitor = C₀The area of the plate = AThe voltage on the battery = V₀The magnitude of the charge in the plate = Q₀The new distance between the plates = 2d What is Capacitance?We know capacitance can be written as,
[tex]C= \dfrac{\epsilon_0 A}{d}[/tex]
where C is the capacitance,
A is the area,
d is the distance and
ε₀ is the electrostatic constant,
Capacitance before,[tex]C= \dfrac{\epsilon_0 A}{d}[/tex]
Capacitance Afterwards,[tex]C= \dfrac{\epsilon_0 A}{2d}[/tex]
[tex]C=\dfrac{1}{2} \times \dfrac{\epsilon_0 A}{d}[/tex]
[tex]C=\dfrac{1}{2} \times C_0[/tex]
What is Voltage(Potential difference)?We know that for the voltage we can write,
[tex]\rm Voltage = \dfrac{Charge}{Capacitance}[/tex]
Voltage before[tex]V=\dfrac{Q_0}{C_0}[/tex]
Voltage Afterwards[tex]V_{new} = \dfrac{Q_0}{C_{new}}[/tex]
[tex]V_{new} = \dfrac{Q_0}{\dfrac{1}{2} \times C_0}[/tex]
[tex]V_{new} = 2 \times\dfrac{Q_0}{C_0}[/tex]
[tex]V_{new} = 2 \times V_0[/tex]
Hence, At a distance of 2d, the potential difference will be twice the potential difference before while the capacitance will be half the value before.
Learn more about Capacitance:
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Which of the following settings describes a displacement vs. time graph that
looks like this?
Displacement
Time
Check all that apply
O A. Constant velocity
OB. Increasing velocity
I C. Zero acceleration
O D. Decreasing acceleration
I NEED HELP ASAP
Answer:
c and a
Explanation:
ape x
A coil with 55 loops has its flux change from 0 Wb to 0.0266 Wb in a certain amount of time, generating 5.22 V of EMF. How much time elapsed?
Answer:
0.280 s
Explanation:
I set it up as 5.22=(55)(0.0266)/x and then solved for x to be 2.80.
A classroom has a volume of 165 m^3. How many moles of gas are in the room if the temperature is 20.0°C and the pressure is 1.00 atm? (Make sure to put P, V, and T in the right units.) (Unit = mol)
The number of mole of the gas present in the room given the data is 0.069 mole
Data obtained from the question Volume (V) = 165 m³Temperature (T) = 20 °C = 20 + 273 = 293 KPressure (P) = 1 atm Gas constant (R) = 8.21 m³.L/Kmol Number of mole (n) =?How to determine the number of mole
The number of mole of the gas present in the room can be obtained by using the ideal gas equation as illustrated below
PV = nRT
n = PV / RT
n = (1 × 165) / ( 8.21 × 293)
n = 0.069 mole
Learn more about ideal gas equation:
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#SPJ1
Answer:
6859 moles
Explanation:
n=(PV)/RT=(100000*165)/(8.21*293 Kelvin)=6859 moles
20 deg Celsius is 293 Kelvin
Please select the word from the list that best fits the definition
Device that measures electric current
Answer:
ammeter
Explanation:
An ammeter is a measuring device used to measure the electric current in a circuit.
Dos masas con valores de 8kg y 12kg cada una se encuentran separadas por una distancia de 1m. Determinar la fuerza de atraccion gravitacional entre ellas si se compara con el valor de sus pesos Como es este valor?
The question is: Two masses with values of 8kg and 12kg each are separated by a distance of 1m. Determine the force of gravitational attraction between them if compared with the value of their weights. What is this value?
Answer: The force of gravitational attraction between them if compared with the value of their weights is [tex]640.704 \times 10^{-11} N[/tex].
Explanation:
Given: [tex]m_{1}[/tex] = 8 kg, [tex]m_{2}[/tex] = 12 kg
Distance = 1 m
Formula used is as follows.
[tex]F = \frac{G \times m_{1} \times m_{2}}{r^{2}}[/tex]
where,
F = force of gravitational attraction
G = gravitational constant = [tex]6.674 \times 10^{-11} N m^{2}/kg^{2}[/tex]
[tex]m_{1}[/tex] = mass of object 1
[tex]m_{2}[/tex] = mass of object 2
r = distance between the centers of these two objects
Substitute the values into above formula as follows.
[tex]F = \frac{G \times m_{1} \times m_{2}}{r^{2}}\\= \frac{6.674 \times 10^{-11} Nm^{2}/kg^{2} \times 8 kg \times 12 kg}{(1 m)^{2}}\\= 640.704 \times 10^{-11} N[/tex]
Thus, we can conclude that the force of gravitational attraction between them if compared with the value of their weights is [tex]640.704 \times 10^{-11} N[/tex].
What is the efficiency of a car's engine when heat input is 400,000 joules and
the waste heat is 300,000 joules?
O A. 25%
B. 35%
O C. 75%
D. 85%
Answer: A. 25%
Explanation: Ap3x
Elements in Group____are common alkaline earth metals.
Answer here
Answer:
Explanation:
k
Answer:
Explanation:
Group 2 consists of the elements in the second column. They all have a combining number (valence number) of 2+ after giving away 2 electrons.They start with Beryllium (element 4 in the periodic table) and end with Radium (element 88 in the periodic table).we are learning about sound waves and pitched. i need to know which glass will make a high pitch and which one will make a low one.
Answer:
the glass that has the most water produces the lowest pitch and the glass with the smaller amount produces the highest pitch
Explanation:
the glass full of water causes the glass to vibrate slower and the sound u hear is at a lower pitch
Please dont delete this question......
Answer:
c
Explanation:
Answer:
C.
Explanation:
What is the gravitational potential energy for a 35 kg box
that is 2.0 m above the ground?
Answer:
PE=mgh = 35x9.8x2
=686J.
compare and contrast current and static electricity plz help.
Static
Type of electron movement: random
path of electrons: unpredictable
duration flow: short
usefulness: stattionery objects
Current
Type of electron movement: steady in a given direction
Path of electrons: can be directed
Duration of flow: long
Usefulness: can power appliances
Note: This is a few notes I know about it sorry if its not what you are looking for This is all the info I have
Which of the following could be included in your gamer's creed that would help keep gamers safe?
A. I will work hard and play harder. Games are my life.
B. I will use privacy features that gaming sites provide to ensure I do not share personal information with strangers.
C. I will do whatever I can to win games I play online.
D. I will share the game equally with my friends and family.
swered
Answer:
The answer is B. I will use privacy features that gaming sites provide to ensure I do not share personal information with strangers.
Explanation:
It keeps you safe online
Answer: the answer is b
Explanation:
PLEASE HELP THIS IS BIG. ITS 2ND GRADE WORK BTW. HELP FOR CROWN AND POINTS!!!!
What did Ben Franklin show with his famous kite experiment?
that lightning is electricity
how sounds could be recorded
that electromagnetic waves could be found and turned into sound energy
how to create a battery
Answer:
your answer is A
Explanation:
brainliest plzzzz
Answer:
c is the correct answer
Multiple Choice
Which is the best reason to be wary of those you talk to on the Internet?
A. They may not be who they say they are.
B. You don't know where they live.
C. You don't know their favorite foods.
D. They may not be in the same grade as you.
3. A 40-gram ball of clay is dropped from a height, h, above a cup which is attached to a spring of spring force constant, k, of 25 N/m. The ball lands in the cup, and the spring compresses a distance, x. If x is 0.506 m, then what is the maximum speed of the ball?
Answer:
the maximum speed of the ball is 12.65 m/s
Explanation:
Given;
mass of the ball, m = 40 g = 0.04 kg
spring constant, k = 25 N/m
Apply the principle of conservation of energy;
The Elastic potential energy of the spring will be converted into Kinetic of the ball;
[tex]\frac{1}{2} kx^2 = \frac{1}{2} mv^2\\\\ kx^2 = mv^2\\\\v^2 = \frac{kx^2}{m} \\\\v = \sqrt{\frac{kx^2}{m}} \\\\v = \sqrt{\frac{(25)(0.506)^2}{0.04}} \\\\v = \sqrt{160.0225} \\\\v = 12.65 \ m/s[/tex]
Therefore, the maximum speed of the ball is 12.65 m/s
A jet plane travels at 40.8 km at an average speed of 340 m/s calculate how long this journey took- giveyour answer to the nearest minute
Answer:
[tex]2\ \text{minutes}[/tex]
Explanation:
d = Distance traveled = 40.8 km
s = Speed of jet = 340 m/s
Time is given by
[tex]t=\dfrac{d}{s}[/tex]
[tex]\Rightarrow t=\dfrac{40.8\times 10^3}{340}[/tex]
[tex]\Rightarrow t=120\ \text{s}[/tex]
[tex]\Rightarrow t=\dfrac{120}{60}=2\ \text{minutes}[/tex]
The time taken to complete the journey is [tex]2\ \text{minutes}[/tex].
for the following equation answer the following:
Al + O2+ heat -----> Al203
1. Balance this chemical reaction
2. What type of chemical reaction is this?
3. is this endothermic or an exothermic reaction
Answer:
4Al + 3O2 + heat ------> 2Al2O3
Explanation:
It is endothermic reaction.
1. What are the two main gases responsible for lowering down the pH.
2. Can we control an acid rain? Why or Why not?
3. When pH changes from 6 to 3, how many times does acidity increase?
Answer:
1. The three main acidic gases responsible for lowering the pH of rainwater are non-metal oxides produced by the burning of fossil fuels like coal, oil and natural gas. Sulfur dioxide is produced when fossil fuels containing sulfur impurities are burned.
2. A great way to reduce acid rain is to produce energy without using fossil fuels. Instead, people can use renewable energy sources, such as solar and wind power. Renewable energy sources help reduce acid rain because they produce much less pollution.
3. The pH scale is logarithmic, meaning that an increase or decrease of an integer value changes the concentration by a tenfold. For example, a pH of 3 is ten times more acidic than a pH of 4.
(please help asap 15 points) Ocean tides are created by...
the spinning of the Earth
heating of the water from
the Sun gravitational pull from the moon and Sun
All of the Above
A 450.0N force is applied for 9.90s, what is the momentum?
Answer:
Momentum = 4455 Ns
Explanation:
Given the following data;
Force = 450 N
Time = 9.9 seconds
To find the momentum;
According to Newton's second law of motion in terms of momentum states that the net force acting on an object is equal to change in momentum divided by time.
Mathematically, it is given by the formula;
Net Force = change in momentum/time
Momentum = force * time
Substituting into the formula, we have;
Momentum = 450 * 9.9
Momentum = 4455 Ns
A 7.0 kg mass is lifted 4.0 m above the ground. Find the change in gravitational energy.
[tex]\mathfrak{\huge{\orange{\underline{\underline{AnSwEr:-}}}}}[/tex]
Actually Welcome to the concept of Graviatoonal Energy.
P = mgh
hence,
E = (7)*(9.8)*(4) = 274.4 joules
==> Energy = 274.4 J
Kamal said the distance from the top of the balloon to the ground in the Example is Ï···· 353 ft. What mistake might Kamal have made? 1 2
Complete question is;
Kamal said the distance from the top of the balloon to the ground in the Example image attached is √353 ft. What mistake might Kamal have made?
Answer:
the mistake Kamal made is that she probably used 17 ft as the perpendicular side of the triangle with b as the hypotenuse instead of using 17ft as the hypotenuse
Explanation:
From the image attached, we can see that the distance from the top of the balloon which is blue in color to the ground is denoted by "b".
Now the triangle is a right angle triangle with hypotenuse = 15ft + 2ft = 17 ft; the adjacent side = 8 ft, while the opposite side is "b".
Thus, we can use pythagoras theorem to solve this as;
b = √(17² - 8²)
b = √(289 - 64)
b = √225
b = 15ft
However,we are told Kamal got b as √353 ft.
From inspection of the calculations we just did, if we had used addition instead of subtraction, we would have gotten b = √353 ft.
Thus, we can under that the mistake Kamal made is that she probably used 17 ft as the perpendicular side of the triangle with b as the hypotenuse instead of using 17ft as the hypotenuse.
How could nanotechnology best be used to improve the treatment of cancer with chemotherapy?
A. A nanometer-size carrier could be designed to bring the chemotherapy drugs only to cancer cells.
B. A nano carbon wire could be designed that would aid in the manufacture of chemotherapy drugs.
C. A quantum dot could be used to watch where the chemotherapy drugs go in the body.
D. Biomaterials could be made that would allow for cell growth within the cancer cells so that they are easier to find.
Answer: A
Explanation: Edg2020
A force of 20 newtons is used to much a box a distance of 2 meters. How much work was done?
Answer:
40 J
Explanation:
In the case of a rectilinear movement, the work is calculated as the product of Force (N) * movement (m). In your case, unless the angle between the force vector and the displacement vector is different from 0, the work is:
20 N * 2 m = 40 J
how to calculate light year, minute and second?
Answer:
A light-year is the distance light travels in one year. How far is that? Multiply the number of seconds in one year by the number of miles or kilometers that light travels in one second, and there you have it: one light-year. It's about 5.88 trillion miles (9.5 trillion km).
Explanation:
Tell the difference between an internal and an external influence and give 1 examples of each.
Answer:
Si tienen diferencia
Explanation: Internas: Proviene de la herencia; el legado genético que las personas reciben de sus padres.
Externa: Provienen de las experiencias personales frente
al mundo exterior
True or False. Can Metalloids conduct electricity under certain conditions?
can metalloids conduct electricity under certain conditions?
true
Write down the name of ten items made of different materials. You have to cover all states
of matter. Prepare a chart which describes the differences in between them by their shape, size,
volume.
Answer:
helium,oxygen, shoe blackboard,juice,coffe,iron,rock,ozoneand water
A bus driver drove from Philadelphia to Washington DC. He drove the first 100km in 2 hours, the next 55km in 1 hour, and the final 75km in 2 hours. What is the average speek of the bus throughout the trip? a 77km/hr b 46km/hr c 81km/hr d 50km/hr
Answer:
b. 46 km/hr
Explanation:
Applying,
S' = d'/t'................... Equation 1
Where S' = Average speed of the bus, d' = Total distance covered by the bus, t' = Total time taken.
From the question,
d' = (100+55+75) km = 230 km
t' = (2+1+2) = 5 hours
Substitute these values into equation 1
S' = 230/5
S' = 46 km/hr.
Hence the correct option is b. 46 km/hr