What does Weber's Law about 'just noticeable differences' predict about how much someone has to change the brightness of a light before we can notice the difference? a. It depends on how bright the light was in the first place - the brighter it was, the less change is needed before we realize it. b. It depends on how long we have been looking at the light - the longer we have been looking, the more change is needed. c. It is always the same amount - 7 lux. d. It depends on how bright the light was in the first place - the brighter it was, the more change is needed before we realize it.
Answer:
answer A is the correct one
Explanation:
Weber's law states that "the smallest discernible change of a stimulus and proportional to the stimulus".
Applying this law to cases of optical intensity, the ratio must be
k = cte = ΔI / I
where ΔI is the variation of the intensity and I is the value of the intensity
In general, for humans, the constant is 0.15 for the rods and 0.015 for the cones of the retina.
When reviewing the answers, answer A is the correct one, since in order for the previous relationship to be maintained, the magnitudes must rise proportionally
how long will a speed boat cross a 2.o km lake with a speed of 40 km/hr
Explanation:
s=d/t
t= d/s
t= 2/40
t= 0.05 hr
Electric charges are either positive or ____
Answer:
Negative
Explanation:
duh
Answer:
:)
Explanation:
negative.
go add the snap carmel.bratz
Which change(s) of state require an increase in energy?
Answer: Melting, evaporation and sublimation.
Melting, evaporation and sublimation require an increase in energy.
To determine the changes of state that require an increase in energy, we need to know about changes of state.
What are the changes of state of a substance?Melting, evaporation and sublimation are the changes of state of a substance.
How do melting, evaporation and sublimation require an increase in energy?In melting process, substance goes from solid to liquid state. In evaporation state, it goes from liquid to vapour state and in sublimation, it goes from solid to vapour state.In each of the above case, the bonds between molecules of the substance become weak due to getting of heat energy. And the heat energy is appeared as kinetic energy of the molecules.So the molecules vibrate rapidly which leads to the change of state.Thus, we can conclude that melting, evaporation and sublimation require an increase in energy.
Learn more about changes of state here:
https://brainly.com/question/18372554
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1. A tourist accidentally drops a camera from a 40.0 m high bridge and it falls for 2.85 seconds. If g = 9.81 m/s2 and air resistance are disregarded, what is the speed of the camera as it hits the water?
I NEED HELP plsssss
Answer:
28 m/s
Explanation:
vf^2=vi^2+2a(delta y)
=sqrt(2* -9.8 m/s^2* -40 m)
=28 m/s
Which statement describes the direction of the current and the magnetic field when the left hand rule is being used?
Answer:
They are perpendicular.
Explanation:
How many atoms of each element are in 4Na3PO4?
A.) 3 sodium, 1 phosphorus, 4 oxygen
B.) 4 sodium, 4 phosphorus, 4 oxygen
C.) 12 sodium, 1 phosphorus, 4 oxygen
D.) 12 sodium, 4 phosphorus, 16 oxygen
Answer:
D) 12 sodium, 4 phosphorus. 16 oxygen
Explanation:
there is a four in front of the full formula, so you multiply all of the sub numbers by 4
The perception of an image first, followed by noticing individual pieces of the
image, can be described as:
A. sensation.
B. perceptual processing.
C. top-down processing.
D. bottom-up processing.
SUBMIT
Answer:
The answer is Top-Down processing
Explanation:
I had this question on a apex quiz and i got it correct.
Because force is a vector measurement, it has both magnitude and
PLZ EXPLAIN AND I WILL GIVE YOU BRANILEST
How do two interacting objects exert equal and opposite forces on each other when they collide, even though they have different masses?
Answer:
Did a little research.
Explanation:
The Law of Action-Reaction:
Newton's third law of motion is naturally applied to collisions between two objects. In a collision between two objects, both objects experience forces that are equal in magnitude and opposite in direction. Such forces often cause one object to speed up (gain momentum) and the other object to slow down (lose momentum). According to Newton's third law, the forces on the two objects are equal in magnitude. While the forces are equal in magnitude and opposite in direction, the accelerations of the objects are not necessarily equal in magnitude. In accord with Newton's second law of motion, the acceleration of an object is dependent upon both force and mass. Thus, if the colliding objects have unequal mass, they will have unequal accelerations as a result of the contact force that results during the collision.Consider the collision between the club head and the golf ball in the sport of golf. When the club head of a moving golf club collides with a golf ball at rest upon a tee, the force experienced by the club head is equal to the force experienced by the golf ball. Most observers of this collision have difficulty with this concept because they perceive the high speed given to the ball as the result of the collision. They are not observing unequal forces upon the ball and club head, but rather unequal accelerations. Both club head and ball experience equal forces, yet the ball experiences a greater acceleration due to its smaller mass. In a collision, there is a force on both objects that causes an acceleration of both objects. The forces are equal in magnitude and opposite in direction, yet the least massive object receives the greatest acceleration.
Consider the collision between a moving seven ball and an eight ball that is at rest in the sport of table pool. When the seven ball collides with the eight ball, each ball experiences an equal force directed in opposite directions. The rightward moving seven ball experiences a leftward force that causes it to slow down; the eight ball experiences a rightward force that causes it to speed up. Since the two balls have equal masses, they will also experience equal accelerations. In a collision, there is a force on both objects that causes an acceleration of both objects; the forces are equal in magnitude and opposite in direction. For collisions between equal-mass objects, each object experiences the same acceleration.
A car traveling 21 m/s is accelerated uniformly at the rate of 2.2 m/s ^2 for 6.9 s. What is the car’s final speed?
Answer:
36m/s
Explanation:
v=u+at
v=21+(2.2×6.9)
v=21+15.18
v=36.18
v=36m/s
I got this information for a lab but I don't know how to do the hypothesis and the conclusion please can you guys help me with it quickly
Answer:
A hypothesis is what you think will happen.
A conclusion is the results of an experiment summarized.
Hope this helps.
Help pls it’s urgent
Answer:
A
Explanation:
Refraction
 explain why earths acceleration is usually very small compared to the acceleration of the object the earth interact with
Answer:
F-ma
Explanation:
If you are speaking of objects like satellites, etc. then their mass is much less than that of the Earth. A good approximation is Newton's first law of motion:
Force = Mass × Acceleration
often written:
F = m a
The gravitational force is the same between the Earth and the object - only the mass differs. So the acceleration is inversely proportional to the mass.
when water in a brook or system of pipes flows from a wide region to a narrow region, the speed of water in the narrow region is
Answer:
more
hope this helps
plz mark brainliest
Why is a control group generally very important in an experiment?
Answer: The control group is the part where you see what happens when you change a variable you want to study/examine. Basically, you need the control group because you need something to see what happens when you change something.
Hope this Helps! :))))
Temperature is a measure of
Answer:
The average kinetic energy
The amount of heat a substance has or the average kinetic energy of particles in a substance
(HURRY I NEED HELP NOW ILL GIVE YOU BRILLIANT). Why do you think it's impossible for an element to appear on only one side of a valid
chemical equation? And I science
Answer:
i got you
Explanation:
Unfortunately, it is also an incomplete chemical equation. ... But if we count the number of oxygen atoms in the reactants and products, we find that there are two oxygen atoms in the reactants but only one oxygen atom in the products.
A +5.00 pC charge is located on a sheet of paper.
(a) Draw to scale the curves where the equipotential surfaces due to these charges intersect the paper. Show only the surfaces that have a potential (relative to infinity) of 1.00 V, 2.00 V, 3.00 V, 4.00 V, and 5.00 V.
(b) The surfaces are separated equally in potential. Are they also separated equally in distance?
(c) In words, describe the shape and orientation of the surfaces you just found.
Answer:
a) V = - x ( σ / 2ε₀)
c) parallel to the flat sheet of paper
Explanation:
a) For this exercise we use the relationship between the electric field and the electric potential
V = - ∫ E . dx (1)
for which we need the electric field of the sheet of paper, for this we use Gauss's law. Let us use as a Gaussian surface a cylinder with faces parallel to the sheet
Ф = ∫ E . dA = [tex]q_{int}[/tex] /ε₀
the electric field lines are perpendicular to the sheet, therefore they are parallel to the normal of the area, which reduces the scalar product to the algebraic product
E A = q_{int} /ε₀
area let's use the concept of density
σ = q_{int}/ A
q_{int} = σ A
E = σ /ε₀
as the leaf emits bonnet towards both sides, for only one side the field must be
E = σ / 2ε₀
we substitute in equation 1 and integrate
V = - σ x / 2ε₀
V = - x ( σ / 2ε₀)
if the area of the sheeta is 100 cm² = 10⁻² m²
V = - x (10⁻²/(2 8.85 10⁻¹²) = - x ( 5.6 10⁻¹⁰)
x = 1 cm V = -1 V
x = 2cm V = -2 V
This value is relative to the loaded sheet if we combine our reference system the values are inverted
V ’= V (inf) - V
x = 1 V = 5
x = 2 V = 4
x = 3 V = 3
These surfaces are perpendicular to the electric field lines, so they are parallel to the sheet.
In the attachment we can see a schematic representation of the equipotential surfaces
b) From the equation we can see that the equipotential surfaces are parallel to the sheet and equally spaced
c) parallel to the flat sheet of paper
Determine the ratio β = v/c for each of the following.
(a) A car traveling 120 km/h.
(b) A commercial jet airliner traveling 270 m/s.
(c) A supersonic airplane traveling mach 2.7. (Mach number = v/vsound. Assume the speed of sound is 343 m/s.)
(d) The space shuttle, traveling 27,000 km/h.
(e) An electron traveling 30 cm in 2 ns.
(f) A proton traveling across a nucleus (10-14 m) in 0.38 ✕ 10-22 s.
Answer:
a) [tex]\beta = 1.111\times 10^{-7}[/tex], b) [tex]\beta = 9\times 10^{-7}[/tex], c) [tex]\beta = 3.087\times 10^{-6}[/tex], d) [tex]\beta = 2.5\times 10^{-5}[/tex], e) [tex]\beta = 0.5[/tex], f) [tex]\beta = 0.877[/tex]
Explanation:
From relativist physics we know that [tex]c[/tex] is the symbol for the speed of light, which equal to approximately 300000 kilometers per second. (300000000 meters per second).
a) A car traveling 120 kilometers per hour:
At first we convert the car speed into meters per second:
[tex]v = \left(120\,\frac{km}{h} \right)\times \left(1000\,\frac{m}{km} \right)\times \left(\frac{1}{3600}\,\frac{h}{s} \right)[/tex]
[tex]v = 33.333\,\frac{m}{s}[/tex]
The ratio [tex]\beta[/tex] is now calculated: ([tex]v = 33.333\,\frac{m}{s}[/tex], [tex]c = 3\times 10^{8}\,\frac{m}{s}[/tex])
[tex]\beta = \frac{33.333\,\frac{m}{s} }{3\times 10^{8}\,\frac{m}{s} }[/tex]
[tex]\beta = 1.111\times 10^{-7}[/tex]
b) A commercial jet airliner traveling 270 meters per second:
The ratio [tex]\beta[/tex] is now calculated: ([tex]v = 270\,\frac{m}{s}[/tex], [tex]c = 3\times 10^{8}\,\frac{m}{s}[/tex])
[tex]\beta = \frac{270\,\frac{m}{s} }{3\times 10^{8}\,\frac{m}{s} }[/tex]
[tex]\beta = 9\times 10^{-7}[/tex]
c) A supersonic airplane traveling Mach 2.7:
At first we get the speed of the supersonic airplane from Mach's formula:
[tex]v = Ma\cdot v_{s}[/tex]
Where:
[tex]Ma[/tex] - Mach number, dimensionless.
[tex]v_{s}[/tex] - Speed of sound in air, measured in meters per second.
If we know that [tex]Ma = 2.7[/tex] and [tex]v_{s} = 343\,\frac{m}{s}[/tex], then the speed of the supersonic airplane is:
[tex]v = 2.7\cdot \left(343\,\frac{m}{s} \right)[/tex]
[tex]v = 926.1\,\frac{m}{s}[/tex]
The ratio [tex]\beta[/tex] is now calculated: ([tex]v = 926.1\,\frac{m}{s}[/tex], [tex]c = 3\times 10^{8}\,\frac{m}{s}[/tex])
[tex]\beta = \frac{926.1\,\frac{m}{s} }{3\times 10^{8}\,\frac{m}{s} }[/tex]
[tex]\beta = 3.087\times 10^{-6}[/tex]
d) The space shuttle, travelling 27000 kilometers per hour:
At first we convert the space shuttle speed into meters per second:
[tex]v = \left(27000\,\frac{km}{h} \right)\times \left(1000\,\frac{m}{km} \right)\times \left(\frac{1}{3600}\,\frac{h}{s} \right)[/tex]
[tex]v = 7500\,\frac{m}{s}[/tex]
The ratio [tex]\beta[/tex] is now calculated: ([tex]v = 7500\,\frac{m}{s}[/tex], [tex]c = 3\times 10^{8}\,\frac{m}{s}[/tex])
[tex]\beta = \frac{7500\,\frac{m}{s} }{3\times 10^{8}\,\frac{m}{s} }[/tex]
[tex]\beta = 2.5\times 10^{-5}[/tex]
e) An electron traveling 30 centimeters in 2 nanoseconds:
If we assume that electron travels at constant velocity, then speed is obtained as follows:
[tex]v = \frac{d}{t}[/tex]
Where:
[tex]v[/tex] - Speed, measured in meters per second.
[tex]d[/tex] - Travelled distance, measured in meters.
[tex]t[/tex] - Time, measured in seconds.
If we know that [tex]d = 0.3\,m[/tex] and [tex]t = 2\times 10^{-9}\,s[/tex], then speed of the electron is:
[tex]v = \frac{0.3\,m}{2\times 10^{-9}\,s}[/tex]
[tex]v = 1.50\times 10^{8}\,\frac{m}{s}[/tex]
The ratio [tex]\beta[/tex] is now calculated: ([tex]v = 1.5\times 10^{8}\,\frac{m}{s}[/tex], [tex]c = 3\times 10^{8}\,\frac{m}{s}[/tex])
[tex]\beta = \frac{1.5\times 10^{8}\,\frac{m}{s} }{3\times 10^{8}\,\frac{m}{s} }[/tex]
[tex]\beta = 0.5[/tex]
f) A proton traveling across a nucleus (10⁻¹⁴ meters) in 0.38 × 10⁻²² seconds:
If we assume that proton travels at constant velocity, then speed is obtained as follows:
[tex]v = \frac{d}{t}[/tex]
Where:
[tex]v[/tex] - Speed, measured in meters per second.
[tex]d[/tex] - Travelled distance, measured in meters.
[tex]t[/tex] - Time, measured in seconds.
If we know that [tex]d = 10^{-14}\,m[/tex] and [tex]t = 0.38\times 10^{-22}\,s[/tex], then speed of the electron is:
[tex]v = \frac{10^{-14}\,m}{0.38\times 10^{-22}\,s}[/tex]
[tex]v = 2.632\times 10^{8}\,\frac{m}{s}[/tex]
The ratio [tex]\beta[/tex] is now calculated: ([tex]v = 2.632\times 10^{8}\,\frac{m}{s}[/tex], [tex]c = 3\times 10^{8}\,\frac{m}{s}[/tex])
[tex]\beta = \frac{2.632\times 10^{8}\,\frac{m}{s} }{3\times 10^{8}\,\frac{m}{s} }[/tex]
[tex]\beta = 0.877[/tex]
A block suspended from a spring is oscillating vertically with a frequency of 4 Hz and an amplitude of 7 cm. A very small rock is placed on top of the oscillating block just as it reaches its lowest point. Assume that the rock has no effect on the oscillation. At what distance above the block’s equilibrium position does the rock lose contact with the block? (hint this occurs when the rock’s acceleration equals the value of gravity) What is the speed of the rock when it leaves the block? What is the greatest distance above the block’s equilibrium position reached by the rock? (Let t = 0 be when the rock is placed on the block)
Answer:
v = - 1,715 m / s , x = 0.0156 m
Explanation:
This is an oscillatory movement exercise, which is described by the expression
x = A cos (wt + Ф)
we can assume that the block is released from its maximum elongation, so the phase constant (Ф) is zero
As we are told that the stone does not affect the movement of the spring mass system, the amplitude and angular velocity do not change, in the upward movement the stone is attached to the mass, but in the downward movement the mass has an acceleration greater than g leave the stone behind, let's look for time, for this we use the definition of speed and acceleration
v = dx / dt
v = - A w sin wt
a = - Aw² cos wt
a = -g
-g = - Aw² cos wt
wt = cos⁻¹ (g / Aw²)
t = 1 / w cos⁻¹ (g / Aw²)
angular velocity and frequency are related
w = 2π f
w = 2π 4
w = 8π rad / s
remember that the angles are in radians
t = 1 / 8π cos⁻¹ (9.8 / (0.07 64π²))
t = 0.039789 1.3473
t = 0.0536 s
let's find the speed for this time
v = - A w sin wt
v = - 0.07 8π sin (8π 0.0536)
v = - 1,715 m / s
the distance is
x = A cos wt
x = 0.07 cos (8π 0.0536)
x = 0.0156 m
If a person has the values for an object's density and volume, what value can be calculated?
o the object's size
o the object's mass
the shape the object forms in a container
the amount of space the object takes up
Answer:
Answer:
The object's mass.
Explanation:
The formula d=m/v.
d --> density
m--> mass
v --> volume
With density and volume given, you can calculate the mass of the object.
Explanation:
square root of 1024 using fractorization method
Answer:
= 32Explanation:
hope that will help you1
A truck increases its speed from 15 m/s to 60 m/s in 15 s. Its acceleration is
In the International Space Station which orbits Earth, astronauts experience apparent weightlessness because:_________
a) the astronauts and the station are in free fall towards the center of the Earth.
b) there is no gravity in space. the station is kept in orbit by a centrifugal force that counteracts the Earth's gravity.
c) the station's high speed nullifies the effects of gravity.
d) the station is so far away from the center of the Earth.
Answer:
a) the astronauts and the station are in free fall towards the center of the Earth
Explanation:
Weightlessness is only a sensation of zero weight, a body experiences when it is in free fall towards the center of the Earth, caused by lack of contact force on such body.
Weightlessness doesn't mean the object has zero actual weight, is just a sensation of no weight due to lack of contact force to produce upward reaction on the object which gives the real sense of ones weight.
Thus, the astronauts experience apparent weightlessness because:
a) the astronauts and the station are in free fall towards the center of the Earth.
Which statement is true about the SI System?
A-Uses different base units than the English measurement system.
B-Is used in scientific
measurement.
C-Includes the meter as its base unit for length.
D-All of the above.
Answer:
maybe the answer is in is D part
Which best describes a reference frame?
Answer: A system or frame of reference are those conventions used by an observer (usually standing at a point on the ground) to be able to measure the position and other physical magnitudes.
Answer:
C a position from which something is observed
om edu 2021
Explanation:
I don't understand why will only the 12 ohms lamps turn on when the switch is in position 2. shouldn't the current flow like this (like I highlighted in the picture)?
You would like to know whether silicon will float in mercury and you know that can determine this based on their densities. Unfortunately, you have the density of mercury in units of kilogrammeter3kilogrammeter3 and the density of silicon in other units: 2.332.33 gramcentimeter3gramcentimeter3. You decide to convert the density of silicon into units of kilogrammeter3kilogrammeter3 to perform the comparison. By which combination of conversion factors will you multiply 2.332.33 gramcentimeter3gramcentimeter3 to perform the unit conversion?
Answer:
The conversion factors you will use to multiply is 1/0.001 or simply 1000 to perform the unit conversion.
Explanation:
To convert from gram/centimeter³ to kilogram/meter³
First,
NOTE:
1 kilogram = 1000 gram, that is 1 gram = 0.001 kilogram; and
1 meter = 100 centimeter, that is 1 centimeter = 0.01 meter
then,
1 meter³ = 1000000 centimeter³, that is
1 centimeter³ = 0.000001 meter³
Now, we can write that
1 kilogram/meter³ = 1000 gram / 1000000 centimeter³
= 0.001 gram/centimeter³
If 1 kilogram/meter³ = 0.001 gram/centimeter³
Then, 1 gram/centimeter³ = 1/0.001 kilogram/meter³ = 1000 kilogram/meter³
Hence, 1 gram/centimeter³ = 1000 kilogram/meter³
∴The conversion factors you will use to multiply is 1/0.001 or simply 1000 to perform the unit conversion.
That is,
2.33 gram/centimeter³ will be 2.33 × 1000 kilogram/meter³
= 2330 kilogram/meter³
What is the net force required to give an automobile with a mass of 2,100 kg an acceleration of 5.4 m/s^2?
Answer:
Net force = 11340 N
Explanation:
Given that,
Mass of an automobile, m = 2100 kg
Acceleration of the automobile, a = 5.4 m/s²
We need to find the net force required for the automobile. The net force is the product of mass and acceleration. It can be given by the formula as follows :
[tex]F=ma\\\\F=2100\ kg\times 5.4\ m/s^2\\\\F=11340\ N[/tex]
So, the net force is 11340 N.