Answer:
jjnn ok jjjmkkmmkijnnkko
Find the least frequency of incident light that will knock electrons out of the surface of a metal with a work function of 3eV.
Answer:
The frequency must be: [tex]725\,\,10^{12} \,Hz[/tex]
Explanation:
If the work function of the metal ([tex]\phi[/tex]) is 3 eV, then we can use the formula for the kinetic energy of an ejected electron:
[tex]KE= h*f-\phi[/tex]
considering for the minimum KE = 0, and using the Plank constant h in eV s as: 4.14 * 10 ^(-15) eV s, to solve for the frequency:
[tex]h*f=\phi\\4.14*10^{-15} * f = 3\\f=3*10^{15} /4.14\,\,\frac{1}{s} \\f=725\,10^{12} \,Hz[/tex]
How much force will a 5 kg rock hit the Earth with if it falls
for 1 second?
Answer:
f
Explanation:
f
Which statement is correct?
A. If the electric field is zero everywhere inside a region of space, the potential must also be zero in that region.
B. When the electric field is zero at a point, the potential must also be zero there.
C. If the electrical potential in a region is constant, the electric field must be zero everywhere in that region.
D. If the electric potential at a point in space is zero, then the electric field at that point must also be zero.
Answer:
The answer is "Choice C ".
Explanation:
The relationship between the E and V can be defined as follows:
[tex]\to E= -\Delta V[/tex]
Let,
[tex]\to E= \frac{\delta V}{\delta x}[/tex]
When E=0
[tex]\to \frac{\delta V}{\delta x}=0[/tex]
v is a constant value
Therefore, In the electric potential in a region is a constant value then the electric-field must be into zero that is everywhere in the given region, that's why in this question the "choice c" is correct.
A dropped ball gains speed because
its nature is to become closer to Earth,
its velocity changes.
a gravitational force acts on it
Of inertia
Answer:
3 and 3 and 3
Explanation:
I am sure Hope for brain list
Explain why two electric charges of the same magnitude, when on a collision course with each other, won't actually collide
(serious answers only)
Answer:
Explanation:
When two charges of equal magnitude and sign approach each other, they interact through Coulomb's law
F = [tex]k \frac{q_ 1q_2}{z^2 }[/tex]k q1 q2 / r2
In you case the house are of equal magnitude and sign
q1 = q2 = q
F = k q2 / r2
Let's analyze this expression, the charge is repulsive on each charge, when they are on a collision course as they approach they feel an electric field opposite to their direction of movement, this field decreases its speed, the closer they get, the greater the repulsive force. , up to the point where this force is equal to or greater than the impulse, therefore the point where the velocity reaches zero, for this reason the particles do not actually touch
A solar panel is used to collect energy from the sun and change it into other forms of energy. The picture below shows some solar panels on the roof of a building. Which form of energy to collected by the solar panels?
A. Wind
B. sound
C. Magnetic
D. Light
An accelerometer has a damping ratio of 0.5 and a natural frequency of 18,000 Hz. It is used to sense the relative displacement of a beam to which it is attached. (a)If an impact to the beam imparts a vibration at 4500 Hz, calculate the dynamic error and phase shift in the accelerometer output. (b)Calculateits resonance frequency.(c)What isthe maximumpossiblemagnitude ratio that the system can achieve
Answer:
A) i) Dynamic error ≈ 3.1%
ii) phase shift ≈ -12°
B) 79971.89 rad/s
Explanation:
Given data :
Damping ratio = 0.5
natural frequency = 18,000 Hz
a) Calculate the dynamic error and phase shift in accelerometer output at an impart vibration of 4500 Hz
i) Dynamic error
This can be calculated using magnitude ratio formula attached below is the solution
dynamic error ≈ 3.1%
ii) phase shift
This phase shift can be calculated using frequency dependent phase shift formula
phase shift ≈ -12°
B) Determine resonance frequency
Wr = 2[tex]\pi[/tex] ( 18000 [tex]\sqrt{0.5}[/tex] ) = 79971.89 rad/s
C) The maximum magnitude ratio that the system can achieve
What two air masses creates hurricanes?
Answer:
The warm seas create a large humid air mass. The warm air rises and forms a low pressure cell, known as a tropical depression.
Explanation:
Hurricanes arise in the tropical latitudes (between 10 degrees and 25 degrees N) in summer and autumn when sea surface temperature are 28 degrees C (82 degrees F) or higher.
Answer:
air
Explanation:
Derase
An electric heater Consumes 1.8 MJ When connected to a 250V supply for 30 minutes. Find the power rating of the heater and the current taken from the supply
Answer:
a. Power = 1000 Watts or 1 Kilowatts.
b. Current = 4 Amperes.
Explanation:
Given the following data;
Energy consumed = 1.8MJ = 1.8 × 10^6 = 1800000 Joules
Voltage = 250V
Time = 30 minutes to seconds = 30 * 60 = 1800 seconds
To find the power rating;
Power = energy/time
Substituting into the equation, we have;
Power = 1800000/1800
Power = 1000 Watts or 1 Kilowatts.
b. To find the current taken from the supply;
Power = current * voltage
1000 = current * 250
Current = 1000/250
Current = 4 Amperes.
A car comes to a bridge during a storm and finds the bridge washed out. The driver must get to the other side, so he decides to try leaping it with his car. The side the car is on is 21.3 m above the river, whereas the opposite side is a mere 2.3 m above the river. The river itself is a raging torrent 54.0 m wide. 1. How fast should the car be traveling just as it leaves the cliff in order to just clear the river and land safely on the opposite side? 2. What is the speed of the car just before it lands safely on the other side?
Answer:
Explanation:
1 ) Let the initial horizontal velocity of car be v .
For vertical displacement
vertical displacement h = 21.3 - 2.3 = 19 m
Time taken to fall by 19 m be t
19 = 1/2 x 9.8 t² ( initial downward velocity is zero )
t = 1.97 s
This is also the time taken to cover horizontal displacement of 54 m which is width of river .
horizontal speed v = 54 / 1.97 m /s
v = 27.41 m /s
2 )
At the time of landing on other side , car will have both vertical and horizontal speed .
vertical speed
v = u + gt
= 0 + 9.8 x 1.97 = 19.31 m /s
horizontal speed will remain same as the initial speed = 27.41 m /s
Resultant speed = √ ( 27.41² + 19.31² )
= √ ( 751.3 + 372.87)
= 33.52 m /s
is 250 000 miles from the earth to the moon" is a qualitative
Observation
TRUE
Or false
Answer:
True
Explanation:
if a car travels 200 m to the east in 8.0 s what is the cars average velocity?
Answer:
25 m/s
Explanation:
200/8 = 25
What is the magnitude of the electric field strength between them, if the potential 7.05 cm from the zero volt plate (and 2.95 cm from the other) is 293 V?
Answer:
E = 4156.02 Vm⁻¹
Explanation:
The magnitude of the uniform electric field between the plates can be given by the following formula:
[tex]E = \frac{\Delta V}{d}\\[/tex]
where,
E = Electric field strength = ?
ΔV = Potetial Difference = 293 V
d = distance between plates = 7.05 cm = 0.0705 m
Therefore,
[tex]E = \frac{293\ V}{0.0705\ m}\\\\[/tex]
E = 4156.02 Vm⁻¹
Consider the balloon and air inside the flask to be a closed system. Use the First Law of Thermodynamics to explain what happened to the balloon as heat was added by the environment.
Consider the balloon and air inside the flask to be in a closed system. Using the First Law of Thermodynamics to explain what happened to the balloon as heat was added by the environment.
Balloon will burst, due to more heat and in another flask air gets heated.
What is the first law of thermodynamics ?"The first law of thermodynamics states that energy can neither be created nor destroyed, only altered in form. For any system, energy transfer is associated with mass crossing the control boundary, external work, or heat transfer across the boundary. These produce a change of stored energy within the control volume."
What is heat ?"Heat is the energy that is transferred from one body to another as the result of a difference in temperature. If two bodies at different temperatures are brought together, energy is transferred i.e, heat flows—from the hotter body to the colder."
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Pls help me I’m failing
Answer:
A is the answer okkkkkkkkkkkkkkkk
Show two data points from your simulation that demonstrate this behavior.
I1 V1 I2= 2I1 V2=2V1 V1/ I1 =V2/I2
For the light bulb, why is it better to take more measurements in the range 20mA < I < 40mA, instead of just taking equally spaced measurements in the entire range of 0 mA < I< 55mA
Answer:
hello your question is incomplete attached below is the complete and the required circuit diagrams
answer :
Ai) This proves that when the current across the resistor is doubled the value of the voltage across the resistor doubles as well
B) It is better to take more measurements in the range 20mA < I < 40mA because of the amount of temperature reached by the bulb and the change in resistance is affected by the temperature
hence At 0 mA current, there won't be any noticeable change
Explanation:
Ai) The voltage across the resistor will double when you double the current through the resistor
Given that : V = I*R.
lets assume : I = 2 amperes , R = 3 ohms
V = 2*3 = 6 v
secondly lets assume double the value of (I) i.e. I = 4 amperes
hence : V = 4*3 = 12 volts
This proves that when the current across the resistor is doubled the value of the voltage across the resistor doubles as well
Aii) Showing the two data points from simulation
I1 V1 I2= 2I1 V2=2V1 V1/ I1 =V2/I2
0.9*10^3 9 * 10^3 1.8*10^3 18*10^3 10 ohms
1.6 * 10^3 16 * 10^3 3.2*10^3 32*10^3 10 ohms
B) It is better to take more measurements in the range 20mA < I < 40mA because of the amount of temperature reached by the bulb and the change in resistance is affected by the temperature
hence At 0 mA current, there won't be any noticeable change
Assume all of the resistors in the following circuits have a value of 5 ohms. Which ammeter will have the highest
reading?
Answer:
Circuit B
Explanation:
To know the correct answer to the question, we shall determine the reading of the ammeter i.e the current in each circuit. This can be obtained as follow:
For circuit A:
Resistance (R) = 5 ohms
Voltage (V) = 1.5 V
Current (I) =?
V = IR
1.5 = I × 5
Divide both side by 5
I = 1.5 / 5
I = 0.3 A
For circuit B:
We'll begin by calculating the total resistance in the circuit. This can be obtained as follow:
Resistance 1 (R₁) = 5 ohms
Resistance 2 (R₂) = 5 ohms
Total resistance (Rₜ) =?
Since they are in parallel connections, the total resistance can be obtained as illustrated below:
Rₜ = R₁ × R₂ / R₁ + R₂
Rₜ = 5 × 5 / 5 + 5
Rₜ = 25 / 10
Rₜ = 2.5 ohms
Finally, we shall determine the current in the circuit.
Resistance (R) = 2.5 ohms
Voltage (V) = 1.5 V
Current =?
V = IR
1.5 = I × 2.5
Divide both side by 2.5
I = 1.5 / 2.5
I = 0.6 A
For circuit C:
We'll begin by calculating the total resistance in the circuit. This can be obtained as follow:
Resistance 1 (R₁) = 5 ohms
Resistance 2 (R₂) = 5 ohms
Total resistance (Rₜ) =?
Since they are in series connections, the total resistance can be obtained as illustrated below:
Rₜ = R₁ + R₂
Rₜ = 5 + 5
Rₜ = 10 ohms
Finally, we shall determine the current in the circuit.
Resistance (R) = 10 ohms
Voltage (V) = 1.5 V
Current =?
V = IR
1.5 = I × 10
Divide both side by 10
I = 1.5 / 10
I = 0.15 A
SUMMARY:
Circuit >>>>>>> Current
A >>>>>>>>>>>> 0.3 A
B >>>>>>>>>>>> 0.6 A
C >>>>>>>>>>>> 0.15 A
from the above calculations, circuit B has the highest ammeter reading.
How much work must be done to raise a 1100kg car 2m above the ground?
Answer:
21560 J
Explanation:
Work = mg*h = 1100*9.8*2 = 21560 J
21560 J work must be done to raise an 1100 kg car 2m above the ground.
Work = mass * gravity * height
= 1100 * 9.8 * 2
= 21560 J
What is work done?In precis, work is carried out whilst pressure acts upon an item to purpose a displacement. 3 portions must be regarded in the way to calculate the quantity of work. The ones 3 portions are force, displacement, and the perspective between the pressure and the displacement.
Paints carried out are elaborated in this type of manner that includes both forces exerted on the body and the whole displacement of the body. This block is preceded by a steady force F. The purpose of this pressure is to move the body a certain distance d in an immediate route in the route of the pressure.
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A-10A twin-jet close-support airplane is approximately rectangular with a wingspan (the length perpendicular to the flow direction) of 17.5 m and a chord (the length parallel to the flow direction) of 3 m. The airplane is flying at standard sea level with a velocity of 200 m/s. If the flow is considered to be completely laminar, calculate the boundary layer thickness at the trailing edge and the total skin friction drag. Assume that the wing is approximated by a flat plate. Assume incompressible flow.
Solution :
Given :
Rectangular wingspan
Length,L = 17.5 m
Chord, c = 3 m
Free stream velocity of flow, [tex]$V_{\infty}$[/tex] = 200 m/s
Given that the flow is laminar.
[tex]$Re_L=\frac{\rho V L}{\mu _{\infty}}$[/tex]
[tex]$=\frac{1.225 \times 200 \times 3}{1.789 \times 10^{-5}}$[/tex]
[tex]$= 4.10 \times 10^7$[/tex]
So boundary layer thickness,
[tex]$\delta_{L} = \frac{5.2 L}{\sqrt{Re_L}}$[/tex]
[tex]$\delta_{L} = \frac{5.2 \times 3}{\sqrt{4.1 \times 10^7}}$[/tex]
= 0.0024 m
The dynamic pressure, [tex]$q_{\infty} =\frac{1}{2} \rho V^2_{\infty}$[/tex]
[tex]$ =\frac{1}{2} \times 1.225 \times 200^2$[/tex]
[tex]$=2.45 \times 10^4 \ N/m^2$[/tex]
The skin friction drag co-efficient is given by
[tex]$C_f = \frac{1.328}{\sqrt{Re_L}}$[/tex]
[tex]$=\frac{1.328}{\sqrt{4.1 \times 10^7}}$[/tex]
= 0.00021
[tex]$D_{skinfriction} = \frac{1}{2} \rho V^2_{\infty}S C_f$[/tex]
[tex]$=\frac{1}{2} \times 1.225 \times 200^2 \times 17.5 \times 3 \times 0.00021$[/tex]
= 270 N
Therefore the net drag = 270 x 2
= 540 N
A boy of mass 60 kg is sledding down a 70 m slope starting from rest. The slope is angled at 15° below the horizontal. After going 20 m along the slope he passes his friend of mass 50 kg, who jumps on the sled. They now move together to the bottom of the slope. The coefficient of kinetic friction between the sled and the snow is 0.12. Ignoring the mass of the sled, find their speed at the bottom.
A garbage truck and a minivan are moving at the same velocity.
Which automobile will have greater momentum and why? Explain your response using Newton’s second law of motion specifically.
If the garbage truck and minivan in Part A get into an accident with each other, how can safety restraints in a car can save a life? Explain your response using one of Newton’s laws.
Which of Newton’s laws of motion act upon the vehicles at the point of impact? Explain your answer.
Answer:
Part A
Newton's second law of motion states that the force applied to an object is directly proportional to the rate of change of momentum that is produced
Mathematically, we have;
F = m·v - m·u/Δt
Where;
m = The mass of the object
v = The final velocity of the object
u = The initial velocity of the object
Δt = The duration of motion of the object during change in velocity
Therefore, given that the mass, 'M', of the truck is larger than the mass, 'm', of the minivan, where the time of change in velocity Δt, and the initial and final velocities of both automobiles are the same such as in a sudden stop, the garbage ruck will exert more force than the minivan, and therefore, the garbage truck has a greater initial momentum before the automobiles are brought to a stop
Part B;
According to Newton's first law of motion, we have;
The use of a seat belt (and airbag for front seated passengers) will prevent dashboard or windscreen for the front passengers or the front seat for the passengers in the back, from being the item that stops the continued forward motion of the passengers in the car, which can lead to injury
Part C; The Newton's law of motion that act on a body at the point of impact is Newton's third law of motion, which states that the action and reaction are equal and opposite
Therefore, the action of the garbage truck on the minivan upon impact is equal to the reaction of the minivan to the force the garbage truck exerts on the minivan
Explanation:
Can a particle move in a direction of increasing electric potential, yet have its electric potential energy decrease? Explain
Answer:
Explanation:
Yes , it is possible .
When a negative charge moves towards a positive charge , it is moving in the direction of increasing electrical potential . In the whole process , its electrical potential energy decreases and its kinetic energy increases .
Actually the potential energy of a negative charge near a positive charge is negative and it is inversely proportional to distance .
V = - Qq / R , When R decreases , the negative value of potential increases . That means potential energy decreases .
Assuming the speed of sound is 340 m/s, what is the most likely speed of the jet shown below?
Well we know it has to be greater than 300,000 km/s since we can't see it.
We can't calculate it any closer than that using the given information.
Calculate the magnitude of the gravitational force exerted by Mercury on a 70 kg human standing on the surface of Mercury. (The mass of Mercury is 3.31023 kg and its radius is 2.4106 m.)
Answer:
2.66×10⁻⁹ N.
Explanation:
From the question,
Applying newton's law of universal gravitation,
Fg = GMm/r²............................... Equation 1
Where Fg = gravitational force, G = universal constant, M = mass of the mercury, m = mass of the human, r = radius of Mercury
Given: M = 3.31023 kg, M = 70 kg, r = 2.4106
Constant: G = 6.67×10⁻¹¹ Nm²/kg²
Substitute these values into equation 1
Fg = 6.67×10⁻¹¹(70×3.31023)/(2.4106²)
Fg = 2.66×10⁻⁹ N.
An ideal heat engine operates between 778 K and 475 K. 267 J of waste heat is exhausted. What is the input heat?
Answer:
Explanation:
Suppose that the turbines of a coal-fired plant are driven by hot gases at a temperature of 886 K. the temperature of the exhaust area is only 305 K, the efficiency of this heat engine
hii guys!! ~ i've comeback again!! could you please help me with an assignment?? i have a couple of i know questions!! thank you for helping me, hehe.
tenise can run the 100 meter dash in 9.77 seconds. what is her speed??
Answer:
Speed = 10.24 m/s.
Explanation:
Given the following data;
Distance = 100m
Time = 9.77
To find her speed;
Speed can be defined as distance covered per unit time. Speed is a scalar quantity and as such it has magnitude but no direction.
Mathematically, speed is given by the equation;
[tex]Speed = \frac{distance}{time}[/tex]
Substituting into the equation, we have;
[tex]Speed = \frac{100}{9.77}[/tex]
Speed = 10.24 meter per seconds.
2. Using a giant screw, a crew does 650 J of work to drill a hole into a rock.
The screw does 65 J of work. What is the efficiency of the screw? Show your
work. Hellpppp
Answer:
42,250
Explanation:
It goes inside=
Displacemt
It does work=
Work done
To find efficiency of jule we do=
Dicplacement × Work done
650 × 65
42,250
Please mark me as a brainlist
You are walking down a straight path in a park and notice there is another person walking some distance ahead of you. The distance between the two of you remains the same, so you deduce that you are walking at the same speed of 1.17 m/s. Suddenly, you notice a wallet on the ground. You pick it up and realize it belongs to the person in front of you. To catch up, you start running at a speed of 2.75 m/s. It takes you 10.5 s to catch up and deliver the lost wallet. How far ahead of you was this person when you started running
Answer:
16.6 m
Explanation:
Let d be the distance the other person is ahead of you. Since the other person is walking at a speed, v = 1.17 m/s, after picking the wallet, the other person moves a distance , vt in time, t = 10.5 s, the total distance covered by you till catch up is D = d + vt.
Also, you moves with a speed of v' = 2.75 m/s in time t = 10.5 s as you pick up the wallet, you covers a distance d' = v't at catch up.
At catch up, D = d'
d + vt = v't
d = v't - vt
d = (v' - v)t
Substituting the values of the variables into d, we have
d = (2.75 m/s - 1.17 m/s)10.5 s
d = (1.58 m/s)10.5 s
d = 16.59 m
d ≅ 16.6 m
So, the other person was 16.6 m ahead of you when you started running.
Can any wan help pls
Answer:
b
Explanation:
because of bonds and the bowl is used for heating purpose
Answer:
I think b not sure but I hope its right and is that the nwea test??
Use the worked example above to help you solve this problem. The amount of charge that passes through a filament of a certain lightbulb in 2.09 s is 1.56 C. (a) Find the current in the bulb. A (b) Find the number of electrons that pass through the filament in 5.24 s. electrons (c) If the current is supplied by a 12.0-V battery, what total energy is delivered to the lightbulb filament
Answer:
a) i = 0.746 A, b) # _electron = 2.44 10¹⁹ electrons, c) E = 1.87 10⁴ J
Explanation:
a) The definition of current is the charge per unit of time
i = Q / t
i = 1.56 / 2.09
i = 0.746 A
b) Let's look for the cargo in passing at this time
i = Q / t
Q = i t
Q = 0.746 5.24
Q = 3.904 C
an electron has a charge e = -1.6 10⁻¹⁹ C, let's use a direct proportions rule
# _electron = 3.904 C (1 electron / 1.6 10⁻¹⁹)
# _electron = 2.44 10¹⁹ electrons
the number of electrons has to be an integer
c) In this part you are asked to calculate the power
P = V i
P = 12 0.746
P = 8.952 W
P = E/t
E = P t
E = 8.952 2.09
E = 1.87 10⁴ J