Answer:
5
Explanation:
The light intensity may be defined as the strength of the light or the magnitude of its brightness that a source of light can produce.
The light threshold is the minimum intensity of the light that our eye can detect and the ability to adapt to darkness.
In the context, Daniel wishes to find if can notice the difference in the intensity of the light when he add 5 candles to the set of 50 candles.
He noticed that when he added 5 candles, he could notice the difference in the intensity and when he added less than 5 candles to the set of 50 candles he could not detect.
Thus, the difference threshold for Daniel to detect the change in the intensity of the light is 5 candles.
When the surface of a metal is exposed to blue light, electrons are emitted. If the intensity of the blue light is increased (so the light is just brighter), what value will also increase?
A. the maximum kinetic energy of the ejected electrons
B. the number of electrons ejected per second
C. the time lag between the onset of the absorption of light and the ejection of electrons
please help!!!
So, we know that this question is about photoelectric effect.
What is photoelectric effect?
-Photoelectric effect is a phenomenon where electrons are released from a material whenever an electromagnetic radiation such as light, hits it.
-This phenomenon is first discovered by Heinrich Rudolf Hertz in 1887 whereas Albert Einstein, in 1905, resolved the conflict between the photoelectric effect and Maxwell's electromagnetic wave theory of light.
Now to your question, the intensity of light only determines the number of the electrons released, not their maximum kinetic energy because this are proportional to the light's frequency.
Also, there is no time lag detected between the entry of radiation and the emission of electrons in experiments held.
So, with letter A and C out, we can therefore conclude that the answer for this is Letter B
The correct answer is B: the number of electrons ejected per second
The Einstein photoelectric equation states that;
[tex]KE = hf - hfo[/tex]
Where
KE = kinetic energy of the ejected photo electrons
h = Plank's constant
f = frequency of incident light
fo = threshold frequency.
The kinetic energy of ejected photoelectrons depends on frequency of incident photon and not on the intensity of the incident photon.
However, the number of photoelectrons ejected per second depends on the intensity of the incident blue light.
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can someone please help
Answer: D
Explanation: because doing a yoga desk program is physical activity, 10k steps is pysical activity, riding a bike or walking/running is also physical activity. so it should be D, all of the above.
Let's say you cut open a log of wood with an axe, what type of simple machine are you using? Does it matter how sharp it is?
yes it matters because if it's not sharp it would take all day
Answer:
an axe is a type of machine called a wedge. it does matter how sharp your axe is. if your axe is not sharp then you will have a harder time cutting wood.
Explanation:
what are the horizontal and vertical components of a vector that is 25units long with an angle of 130 degrees
Answer:
The horizontal component of the vector is approximately -16.07
The vertical component of the vector is approximately 19.15
Explanation:
A vector quantity is a quantity that posses both magnitude and direction specifications
The magnitude of the given vector, R = 25 units
The direction of the vector, θ = 130°
Therefore the location of the vector, starting from the origin of the Cartesian plane, is in the second quadrant having an angle of 180° - 130° = 50° to the horizontal
Given that the x-coordinate is negative in the second quadrant, we have;
The horizontal component of the vector, Rₓ = The x-coordinate of the vector = R×cos(θ)
∴ The horizontal component of the vector, Rₓ = 25 × cos(130°) = -25 × cos(50°) ≈ -16.07
The horizontal component of the vector, Rₓ ≈ -16.07
The vertical component of the vector, [tex]R_y[/tex] = The y-coordinate of the vector = R×sin(θ)
∴ The vertical component of the vector, [tex]R_y[/tex] = 25 × sin(130°) ≈ 19.15
The vertical component of the vector, [tex]R_y[/tex] ≈ 19.15
The vector can be resolved as R = -16.07·i + 19.15·j
Please help me :))
Which golf ball would hit the surface with the greatest impact: a ball that fell one meter above the surface of the Earth or a ball that fell one meter above the surface of the Moon?
Answer:
the one above the surface of earth
Explanation:
earth has gravity the ball of the moon would float away
5. A wire, resistance 23.6 carries a current. 5.9 A. What is the
potential difference across the wire?
a. V = 139 V
c. V=4V
b. V = 17.7 V
d. V = 0.25 V
Answer:
d
Explanation:
Answer:
B
Explanation:
A 45000 watt crane operating at full power lifts a 2100 kg object vertically for 17.4 seconds. How high has the crane lifted the object?
Answer:
Explanation:
We need the power equation here, which is:
Power = (F * Δx)/time
where F * Δx is the amount of work done.
F is a force which is measured in Newtons. We are given the mass of the object, but since we need a Force measure, we need the weight of the object:
F = 2100(9.0)
F = 21000 to the correct number of sig dig.
Now we can plug in the values we have and solve for the displacement, Δx:
[tex]45000=\frac{21000x}{17.4}[/tex] and isolating x:
[tex]\frac{17.4(45000)}{21000}=x[/tex] so
x = 37 m
Amelia is doing an experiment in which she is
going to burn various solid chemicals to see the
colors of flames they produce. For this laboratory
experiment, what types of safety precautions
should she take?
tie hair back
leave open flame unattended to get a drink
only burn the amount of chemicals as
directed by the lab procedure
put out the flame with water from the eyewash
station
Answer:
tie hair back
only burn the amount of chemicals as
directed by the lab procedure
Explanation:
The correct safety precautions for Amelia to take from the options would be to tie her hair back and to only burn the amount of chemicals recommended by the lab procedure.
With her hair left flowing freely, Amelia runs the risk of the hair catching flame while trying to burn the chemicals according to the procedure. Hence, tying her hair up into one neat bunch will limit the risk of it catching fire while working in the lab.
Also, burning less or more than the amount of chemicals recommended by the procedure may be dangerous or hinder Amelia from getting the right result.
Answer:
1,3
Explanation:
just did it
Loops spaced further apart create a stronger electromagnet. True or False
Answer:
False
Explanation:
Electromagnetic strength is inversely proportional to separation distance
What is the three-body problem? Explain at a level so an 8th grader could understand
Answer:
In physics and classical mechanics, the three-body problem is the problem of taking the initial positions and velocities (or momenta) of three point masses and solving for their subsequent motion according to Newton's laws of motion and Newton's law of universal gravitation.[1] The three-body problem is a special case of the n-body problem. Unlike two-body problems, no general closed-form solution exists,[1] as the resulting dynamical system is chaotic for most initial conditions, and numerical methods are generally required.
Hope this answer is right!
Select the correct answer
If the resistance in a circuit remains constant, what happens to the electric power when the current increases?
OA. The power will increase.
OB.
The power will decrease,
OC. There will be no power.
OD
The current does not affect the power,
Reset
Next
[tex]\large\mathrm{A. Power\:\: will \:\:Increase }[/tex]
Explanation :We know that,
[tex]\large \mathrm{ \boxed{P = I²R}}[/tex]
where,
P = electric powerR = resistanceI = electric currentAnd when resistance is constant, the power of the circuit will change proportionally with the change in electric current. therefore, if current increases then the electric power of the circuit will increase too.
[tex]\large\mathfrak{{\pmb{\underline{\orange{hope \: \: i t \: \: helps \: \: you}}{\orange{.....}}}}}[/tex]
Convergent boundaries are responsible for
Answer:
A
Explanation:
The plate collisions that occur in these areas can produce earthquakes, volcanic activity, and crustal deformation.
hope it helps you
As an IT technician for your company, you have been notified that the Windows domain does not seem to be functioning properly. Being familiar with domains, you are fairly confident you know what the issue is. But just to be safe, you take the applicable time to gather additional information and to identify what, if anything, has changed.
Which of the following is the BEST next step?
A. Determine the appropriate fix.
B. Create a hypothesis.
C. Implement the fix.
D. Identify what has changed.
E. Gather information.
Answer: Create a hypothesis
Explanation:
From the information given, information has been gathered and the identification to ascertain if there's a change. Then, an hypothesis has to be created in order to know what the problem is.
One has to carry out some research in order to know what went wrong and should also validate the hypothesis by consulting with ones peers. By doing this, the most likely causes of the issues will be gotten.
What's the meaning of longitudinal?
Answer:
A longitudinal study is a research design that involves repeated observations of the same variables over short or long periods of time. It is often a type of observational study, although they can also be structured as longitudinal randomized experiments.
Explanation:
Đặt vào đầu hai dây dẫn cùng một hiệu điện thế bằng nhau U,có điện trở lần lượt là R1 và R2.Ta thấy cường độ dòng điện qua dây dẫn thứ nhất I1 lớn gấp hai lần cường độ dòng điện qua dây dẫn thứ hai I2
Answer:
The resistance ratio of first conductor to the second conductor is 1 : 2.
Explanation:
Current in first conductor = I1
Current in second conductor = I2 , I1 = 2 I2
According to the Ohm's law
[tex]V= I_1R_1..... (1)\\V = I_2 R_2 .... (2)\\[/tex]
From (1) and (2)
[tex]I_1 R_1 = I_2 R_2\\\\2I_2 R_1 = I_2 R_2\\\\2 R_1 = R_2[/tex]
electromotive force in a circuit;
A) causes free electrons to flow
B) increases the circuit resistance
C) maintains circuit resistance
D) it needed to make the circuit complete
Answer:
A causes free electrons to flow
Explanation:
The amount of force that causes electrons to flow in a conductor is called electromotive force.
what current flows between a voltage of 120v across a resistance of 30Ω?
Answer:
4 amp
Explanation:
From ohm's law,
V=IR
so,
I=V/R
I=120/30
I=4amp ans..
I am confused and need help with the question above??
Convert 162 km/h into m/s.
Answer:
45 m/s
Explanation:
162 / 3.6 = 45 m/s
Divide by 3.6 to convert km/h to m/s.
A trip is taken that passes through the following points in order
Point A Om
Point B 15.0 m
Point C -30.0 m
Point D 20.0 m
Point E -10.0 m
Point F 5.0 m
What is the displacement from Point B to Point E?
A) 5.0 m right
B) 85 m right
C) 25.0 m left
D) 85 m left
Answer:
The displacement from point B to point E is 25.0 m left
PLEASE HELP WITH THIS QUESTION
What of Newton's 3 laws is represented in this picture?
Answer:
The first law states that an object at rest will stay at rest, and an object in motion will stay in motion unless acted on by a net external force. Mathematically, this is equivalent to saying that if The second law states that the rate of change of momentum of a body over time is directly proportional to the force applied, and occurs in the same direction as the applied force. the net force on an object is zero, then the velocity of the object is constant. The third law states that all forces between two objects exist in equal magnitude and opposite direction: if one object A exerts a force FA on a second object B, then B simultaneously exerts a force FB on A, and the two forces are equal in magnitude and opposite in direction
Explanation:
A man can jump 2 m on the surface of the earth, calculate the height that he can jump on the surface of the moon?
Answer:
hi
Explanation:
it is probably 12 m on the surface of the moon
have a good day
I hope this is help full to you
A piece of iron has a mass of 30 g and its volume is 6.2 cm3. What is its density?
Answer:
Density = 4.84 g/cm³
Explanation:
Given the following data;
Mass = 30 g
Volume = 6.2 cm³
To find the density of the piece of iron;
Density can be defined as mass all over the volume of an object.
Simply stated, density is mass per unit volume of an object.
Mathematically, density is given by the equation;
[tex]Density = \frac{mass}{volume}[/tex]
Substituting into the equation, we have;
[tex]Density = \frac{30}{6.2}[/tex]
Density = 4.84 g/cm³
5. What type of chemical reaction is shown?
1 point
2 AgNO3 + CuCl2
-
2 AgCl + 2 Cu(NO3)2
Synthesis
Decomposition
Singe Replacement
Double Replacement
Combustion
Answer:
double Replacement
Explanation:
The mutual replacement of radical and ions between the two compounds or molecules is called double replacement.
General equation : AB+CD = AD +B
give an example of a body with uniform acceleration
Answer:
A ball rolling down the slope.
A bicycle rider is riding the bicycle on tthe slope where both pedals are engaged.
2. CaCl2 (s) + 2H20 ---> Ca(OH)2 (aq) + 2HCl (g) + heat
Is it an endothermic reaction?
Answer:
no
Explanation:
Calcium chloride is a chemical compound made up of calcium ions and chlorine ions. ... Mixing calcium chloride with water is an exothermic reaction, which means that the combination of the two substances releases heat. Thus, when you add calcium chloride to water, the solution heats.
If the light ray hits the first mirror and continues to bounce off the other mirrors inside the box, determine where the light ray will eventually hit on the border
Answer: Light ray X will eventually hit the borader
Explanation:
Which state has the most fixed shape?
O A. Gas
O B. Solid
O C. Liquid
O D. Plasma
Answer: Liquid
“A substance will take on the shape of an open container if it is a Liquid. Explanation: The major state of matter are solid, liquid and gas. Liquid usually have a definite volume.”
Answer:
solid
Explanation:
Solids are fixed and solid.
A motor has an internal resistance of 12.1 Ω. The motor is in a circuit with a current of
4.0 Amps
What is the voltage?
Answer:
Explanation:
V = I * R
V = 4 * 12.1 = 48.4 v
Q) A farmer moves along the boundary of a
square field of side 10 min 40 s .What will
be the magnitude of displacement of the
farmer at the end of 2 minutes 20 seconds
from his initial position?