Answer:
Option B
Explanation:
As we know
Frequency (F) * wavelength (W) = C (speed of light - can also be taken as constant)
Hence,
[tex]F1 W1 = C\\F2W2 = C[/tex]
Or [tex]F1W1 = F2W2[/tex]
Substituting the given values, we get -
[tex]840 *2.5 = 500 *XX = 4.2[/tex] m
Hence, option B is correct
2.
Which of the following has the greatest momentum?
A.
0.2 kg ball moving at 40 m/s
В.
500 kg car traveling at 16 m/s
С.
2000 kg truck traveling at 9 m/s
D
50 kg child skateboarding at 4 m/s
Answer:
I'm corona positive and isolated feeling depressed just logged in to talk someone but people ignoring me thanks for this behaviour got disappointed bye everyone logging out had a great time
A positive point charge is placed at 5 cm from a negatively charged plate.
it is then pulled away from the plate, so it is 10 cm from the plate. Describe
what happened to the potential energy of the charge. (Hint what
happened to the force on the charge more force means more potential
energy) *
Answer: I'm not sure about this one, but you can go to this link to understand it better https://youtu.be/wEQxtUwiV1E.Its a Khan Academy Video Hope This Helps
Explanation:
Which type of energy is the original source for the energy that food molecules can provide?
Answer:
Chemical potential energy
Explanation:
which is used to for any form of energy.
An outside thermometer reads 57°F. What is this temperature in °C? Round your answer to the nearest whole number. 14 49 71 135
Answer:
An outside thermometer reads 57°F. What is this temperature in °C? Round your answer to the nearest whole number.
14
49
71
135
answer is A:14
Explanation:
The temperature of the thermometer which reads 57 °F in degree celsius (°C) to the nearest whole number is 14 °C
Conversion formulaWe can convert from degree celsius (°C) to degree Fahrenheit (°F) with the following equation
°C = 5/9(°F – 32)
How to determine the temperature in degree celsius (°C) Temperature (°F) = 57 °FTemperature (°C) =?°C = 5/9(°F – 32)
°C = 5/9(57 – 32)
°C = 5/9 × 25
°C = 14 °C
Thus, the temperature in degree celsius (°C) of the thermometer is 14 °C
Learn more about conversion:
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how long would it take a leopard, running at an average speed of 20 m/s to travel 500 m?
Answer:
25 seconds
Explanation:
500/20
What is the relationship between large amplitude waves and small amplitude waves?
A Both waves have variable energy.
B Large amplitude waves have more energy than small amplitude waves.
C Large amplitude waves have less matter than small amplitude waves.
D Both waves have constant matter.
Answer:
c.large amplitude waves have less matter than small amplitude waves
A metal rod is 25.000 cm long at 25.0 degrees Celsius. When heated to 102.0 degrees Celsius, it is 25.054 cm long. What is the coefficient of linear expansion for this metal.
A car travels 140 miles in 3 hours. What is its velocity?
Answer:
46.67 miles/s
Explanation:
...........
The left end of a spring is attached to a wall. When Bob pulls on the right end with a 200 N force, he stretches the spring by 20 cm. The same spring is then used for a tug-of-war between Bob and Carlos. Each pulls on his end of the spring with a 200 N force. How far does the spring stretch
Answer:
40 cm
Explanation:
Since Bob pulls with a force of F = 200 N when the spring is attached to the wall and it extends a length x = 20 cm, from Hooke's law,
F = kx where k = spring constant
So, k = F/x = 200 N/20 cm = 10 N/cm
Now, sine both Bob and Carlos pull with a force of F = 200 N in opposite directions, the spring stretches about its center and has an extension, x' in each direction.
So, from F = kx
x = F/k = 200 N/10 N/cm = 20 cm
So, the spring stretches 20 cm in both directions.
So, the total extension is thus x' + x' = 2x' = 2(20 cm) = 40 cm
The spring will stretch 40 cm.When a force is act om the spring the spring will stretch or compress depeds on the application of force.
What is hooke's law?Hooke's law states that the force used to extend the spring is directly equal to the amount of stretch.
The force needed to extend the spring is proportional to its displacement. It is stated as
F=Kx
The given data in the problem is;
F is the force of pull to bob= 200 N
x is the length of extension= 20 cm.
F' is the force act on the another end= 200 N
According to Hooke's law,
[tex]\rm F = Kx \\\\ \rm K= \frac{F}{x} \\\\ \rm K= \frac{200}{20} \\\\ \rm K=10 \ N/cm[/tex]
The extension due to another end force is found by;
[tex]\rm x' = \frac{F}{K} \\\\ \rm x' = \frac{200}{10} \\\\ \rm x' = 20[/tex]
The total extension of the spring will be;
[tex]\rm x_t = x+x' \\\\ \rm x_t = 2(20) \\\\ \rm x_t =40\ cm[/tex]
Hence the spring will stretch 40 cm.
To learn more about the hooke's law refer to the link;
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1.45 L of 16°C water is placed in a refrigerator. The refrigerator's motor must supply an extra 10.7 W power to chill the water to 6°C in 0.7 hr. What is the refrigerator's coefficient of performance?
Answer:
The coefficient of performance of the refrigerator is 2.251.
Explanation:
In this case, the coefficient of performance of the refrigerator ([tex]COP[/tex]), no unit, is equal to the ratio of the heat rate received from the water to the power needed to work, that is:
[tex]COP = \frac{\dot Q_{L}}{\dot W}[/tex] (1)
[tex]COP = \frac{\rho\cdot V\cdot c_{w}\cdot \Delta T}{\dot W \cdot \Delta t}[/tex] (2)
Where:
[tex]\dot Q_{L}[/tex] - Heat rate received from the water, in watts.
[tex]\dot W[/tex] - Power, in watts.
[tex]\rho[/tex] - Density of water, in kilograms per cubic meter.
[tex]V[/tex] - Volume of water, in cubic meters.
[tex]c_{w}[/tex] - Specific heat of water, in joules per kilogram-degree Celsius.
[tex]\Delta T[/tex] - Temperature change, in degrees Celsius.
[tex]\Delta t[/tex] - Cooling time, in seconds.
If we know that [tex]\rho = 1000\,\frac{kg}{m^{3}}[/tex], [tex]V = 1.45\times 10^{-3}\,m^{3}[/tex], [tex]c_{w} = 4187\,\frac{J}{kg\cdot ^{ \circ}C}[/tex], [tex]\Delta T = 10\,^{\circ}C[/tex], [tex]\dot W = 10.7\,W[/tex] and [tex]\Delta t = 2520\,s[/tex], then the coefficient of refrigeration of the refrigerator is:
[tex]COP = \frac{\rho\cdot V\cdot c_{w}\cdot \Delta T}{\dot W \cdot \Delta t}[/tex]
[tex]COP = 2.251[/tex]
The coefficient of performance of the refrigerator is 2.251.
A 13 500 N car traveling at 50.0 km/h rounds a curve of radius 2.00 × 102 m. Find the following: a. the centripetal acceleration of the car b. the centripetal force c. the minimum coefficient of static friction between the tires and the road that will allow the car to round the curve safely
Answer:
a. 0.947 m/s^2
b. 1304.54 N
c. 0.0966
Explanation:
mass of car = 13500 N = 13500/9.8 = 1377.55 kg
velocity = 50 km/h = 50,000 m/h = 13.9 m/s
raidus = 204 m
a. centripetal acceleartion = v^2/r = 13.9^2/204 = 0.947 m/s^2
b. centripetal force = m*centripetal acceleration = 1377.55 * 0.947 = 1304.54 N
c. In order for the car to round the curve safely, static friction = centripetal force
static friction = coefficient of friction (mu) * mg = mu* 1377.55*9.8 = 13500mu
13500mu = 1304.54
mu = 1304.54/13500 = 0.0966
The acceleration, force and coefficient of friction is required.
Centripetal acceleration is [tex]0.965\ \text{m/s}^2[/tex]
Centripetal force is [tex]1328\ \text{N}[/tex]
Coefficient of friction is [tex]0.1[/tex]
N = Weight of car = 13500 N
v = Velocity = [tex]50=\dfrac{50}{3.6}=13.89\ \text{m/s}[/tex]
r = Radius = [tex]2\times 10^2\ \text{m}[/tex]
m = Mass of car = [tex]\dfrac{N}{g}[/tex]
g = Acceleration due to gravity = [tex]9.81\ \text{m/s}^2[/tex]
Centripetal acceleration is
[tex]a_c=\dfrac{v^2}{r}\\\Rightarrow a_c=\dfrac{13.89^2}{2\times 10^2}\\\Rightarrow a_c=0.965\ \text{m/s}^2[/tex]
Force is given by
[tex]F_c=ma_c\\\Rightarrow F_c=\dfrac{N}{g}a_c\\\Rightarrow F_c=\dfrac{13500}{9.81}\times 0.965\\\Rightarrow F_c=1328\ \text{N}[/tex]
Coefficient of friction is given by
[tex]\mu=\dfrac{F_c}{N}\\\Rightarrow \mu=\dfrac{1328}{13500}\\\Rightarrow \mu=0.098\approx 0.1[/tex]
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Show that liquid pressure is directly
proportional to height of liquid in a vessel.
Answer:
P=F/A where F is the weight of the water and A is the area on which it is resting. The weight of the water is mg. The mass of the water is dv where d is the density and v is the volume. Finally, the volume of the water in a vessel is equal to the area of the base of the vessel times the height of the vessel. (v=Ah)
Plugging everything in we get:
P = dAhg/A
So
P=dhg
So we have shown that liquid pressure is directly proportional to height of liquid in a vessel.
make p the subject of the relation 3t-pqq
=2(pn)
Answer:
Explanation:
Add pqq to both sides
3t = pqq + 2 pn Pull out p as a common factor.
3t = p(qq + 2n) Divide by qq + 2n
3t/(qq + 2n)
Write a 4-5 sentences paragraph explaining how one of the following organisms with adapt to a new environment (what adaptations would they not need and what ones what they need?What would they eat?)
1. Polar bear moving to a tropical rainforest.
2. Lizard moving to the North Pole
Be Creative!!!!!
No googling! Or no links
Answer:
We're supposed to write a 4-5 paragraph essay for only 6 points...sorry but no
Explanation:
A skier traveling downhill has this type of energy
Answer:
potential energy
Explanation:
how to spot homogeneous and heterogeneous mixtures
What happens, if anything, when you change the mass of the planet? Why do you think the mass of the planet does, or does not, affect the orbit of the planet?
Answer:
We know that the gravitational force between two objects of mass M1 and M2 that are at a distance R, is given by:
F = G*(M1*M2)/R^2
Where G is a constant.
If you reduce one of the masses, then the gravitational force between the objects will change.
So if we take un account the Earth and the Sun, when you reduce the mass of Earth, the force between Earth and the Sun will decrease, and this will change the orbit of the Earth around the Sun.
(The orbit also depends on the gravitational force between the Earth and the other planets in the system, and all those forces also change, which also has an impact in the orbit change)
If water is flowing in a 1-inch diameter pipe with an average velocity of 3 m/s and the wall roughness is 400 microns, calculate the wall shear stress.
Answer:
Shear stress is 50.63 Pascal
Explanation:
As we know shear stress = [tex]\frac{\rho V^2 f}{8} \\[/tex]
Rho is the density
V is the velocity
f is the value from Moody's chart
We will know determine Reynolds number to determine the flow type and then the f value
[tex]R_e = \frac{ \rho*V*D}{u}[/tex]
[tex]R_e = \frac{1000*3*0.0254}{0.001} = 76200[/tex]
This is a turbulent flow and hence the roughness index is [tex]\frac{E}{D} = 0.0157[/tex], From this we get f = 0.045
Now shear stress = [tex]\frac{1000 * 3^2 * 0.045}{8} = 50.63[/tex] Pa
At high elevations or high latitudes, some of the water that falls on land does not immediately soak in , run off, evaporate or transpire. where is the water being temporarily stored?
Answer:
The water is stored in ice sheets and as snow
Explanation:
Temperature reduces with an increase in altitudes. The standard laps rate is 6.5°C per 1,000 m gained in elevation
At very high elevations, therefore, the air is usually very cold such that when an elevation of 4,500 meters is reached at the equator, it is possible to observe snowfall and the water remain temporarily stored on the surface of the mountain as ice and snow
Which person below is likely to have better health?
A. Jenna, who is optimistic about life
B. Albert, who thinks that events in his life are not in his control
C. Peter, who is depressed
D. Claire, who blames everyone else for her circumstances
SUBMIT
Jenna, who is optimistic about life, is likely to have better health. Hence, option (A) is correct.
What is mental health?Mental health affects cognition, perception, and behavior and includes emotional, psychological, and social well-being. It also affects how someone responds to stress, interacts with others, and makes decisions.
Subjective well-being, perceived self-efficacy, autonomy, competence, generational reliance, and self-actualization of one's intellectual and emotional potential are only a few examples of what is considered to be mental health.
The ability to enjoy life and strike a balance between daily activities and endeavors to develop psychological resilience may be considered a sign of mental health from the viewpoints of positive psychology or holistic approaches.
Learn more about mental health here:
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Which human activity causes the most erosion?
А
building a bridge over a river
B
cutting down trees for lumber
С
building a dam in a stream
D
planting crops in a field
Answer:
B
Explanation:
Do you think the plan for the skyscraper in California is appropriate based on its location? Why or why not? Your answer should include at least three complete sentences. (plz write out answer) (this is about earth quakes)
Answer:
No
Explanation:
No because like my other answer if we put to many diesels on it it will crack and little by little it will break eventually everyone will come tumbling into the water making them drown because they can't get the buckles loose or they wanted to save their families lives
How would you classify an EM wave with a frequency of 10^7 Hz?
Answer:
I think it is television and radio wave
_______ are considered to be fluids.
Solids
Liquids only
Gases only
Liquids and gases
Answer:
liquids and gases
Explanation:
Liquids and gases are considered to be fluids because they yield to shearing forces, whereas solids resist them.
A 5000kg elephant steps into a large spring and compresses it from 1m long to 50cm long what is the spring constant of the spring
Answer: 98 kN/m
Explanation:
Given
Mass of elephant [tex]m=5000\ kg[/tex]
Spring compresses from [tex]1\ m\ (100\ cm) \text{to}\ 50\ cm[/tex]
i.e. change in length is [tex]100-50=50\ cm[/tex]
spring force is given by [tex]kx[/tex]
where k=spring constant
x=change in length
The weight of elephant must be equal to the spring force
[tex]\Rightarrow W=kx\\\Rightarrow 5000\times 9.8=k\times 0.5\\\Rightarrow k=98,000\ N/m\ or\ 98\ kN/m[/tex]
I’ll mark brainliest
When you look into your bathroom mirror, are you upside down
(inverted) or right side up (upright)?
Is this a real or virtual image?
Why?
What is the focal length of a bathroom (flat) mirror?
Answer:
When the image distance is positive, the image is on the same side of the mirror as the object, and it is real and inverted. When the image distance is negative, the image is behind the mirror, so the image is virtual and upright.
Explanation:
Which of the following are the two factors used to calculate average
speed? *
a. total acceleration and total time
b. velocity and time
c. total distance and total time
d. motion and time
Answer:
i think its its c but im not positive :>
Explanation:
If the current of a circuit is 1.5 A, and the power is 24 W. what is the resistor?
Answer:
The resistor has a resistance of 10.667 ohms.
Explanation:
By Ohm's Law, voltage ([tex]V[/tex]), in volts, is directly proportional to the current ([tex]i[/tex]), in amperes, and by definition of power ([tex]\dot W[/tex]), in watts, we have the following formula:
[tex]\dot W = i^{2}\cdot R[/tex] (1)
Where [tex]R[/tex] is the resistance, in ohms.
If we know that [tex]\dot W = 24\,W[/tex] and [tex]i = 1.5\,A[/tex], then the resistance of the resistor is:
[tex]R = \frac{\dot W}{i^{2}}[/tex]
[tex]R = 10.667\,\Omega[/tex]
The resistor has a resistance of 10.667 ohms.
Two point charges, Q1 = -1.0 PC and Q2 = +3.0 PC, are placed as shown in the diagram.
What is the vertical component of the electric field at the origin? Let the constant k = 9.0 x
109Nm²/C2
2.2 m
2.1 m Q1
O A zero
O B. -2100 N/C
O
C. 2100 N/C
o D. -8900 N/C
E. 8900 N/C
NEED ANSWER NOW
NO LINK
A cyclist travels 21 km in 90 minutes. Calculate, in m s–1 , the speed of the cyclist.
Answer:
35/9 m/s
Explanation:
21 km = 21000 m
90 min = 90*60 s = 5400 s
21000/5400 = 35/9 m/s
