Answer: Visual acuity: sharpness of vision.
Myopia: nearsightedness
Refraction: bending of light rays.
Emmetropia: normal vision.
Accommodation: changes the shape of the eye lens to focus light on the retina.
Presbyopia: age-related farsightedness due to loss of elasticity in the lens.
Astigmatism: reduction in visual acuity due to changes in the cornea or lens.
Hyperopia: farsightedness
Myopia and hyperopia are refractive errors of the eye.
Presbyopia occurs in old age people.
Explanation:
Visual acuity: It can be defined as the inability to observe the details of shape of the object. Person loses sharpness in vision.
Myopia: It is a defect in vision in which person is able to observe the near by objects clearly but not able to see the distant objects.
Refraction: It can be defined as the bending of beam of light when it passes through from one substance to another.
Emmetropia: It is a vision without any defect.
Accommodation: It is the ability of the eye to adjust its focal length and adjusting the light on focus.
Presbyopia: It can be defined as the loss of ability of eye to focus on the object. It occurs in old age.
Astigmatism: It is a refractive error in which the eye does not focus light on retina.
Hyperopia: It is also called as farsightedness. Distant objects can be seen clearly but nearby appears blurry.
While skiing in Jackson, Wyoming, your friend Ben (of mass 63.2 kg) started his de- scent down the bunny run, 11.5 m above the bottom of the run. If he started at rest and converted all of his gravitational potential energy into kinetic energy, what is Ben's kinetic energy at the bottom of the bunny run? Use g = 9.8 m/s² Answer in units of J.- answer :7100J part 2 of 2 What is his final velocity? Answer in units of m/s.
Answer:
12.3 m/s
Explanation:
To calculate the final velocity of Ben, we can use the equation KE = 1/2mv^2, where KE is the kinetic energy and m is the mass of Ben. Inserting the given values, we get:
7100 = 1/2 (63.2 kg) v^2
Therefore, v^2 = 7100/31.6
v = √(7100/31.6)
v = 12.3 m/s
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Which has more momentum, a 0.5kg toy car moving a 5 m/s or a 1000kg real car that is
parked?
Answer:
The toy car
Explanation:
the real car is parked so yeah but maybe in some way technically the real car has more "momentum"
Ruby was training for a race at the high school track. She took her dog walked 2250 meters in 15 minutes. Calculate the average speed
Answer:
Average speed [tex]= 2.5[/tex] meter per second
Explanation:
Given
The total distance walked [tex]= 2250[/tex] meters
The total time taken to walk [tex]2250[/tex] meters is [tex]15[/tex] minutes
In one minute there are [tex]60[/tex] seconds
As we know Average speed is equal to total distance travelled divided by total time taken
Hence,
Average speed
[tex]\frac{2250}{15*60} \\2.5[/tex]meter per second
A 62.3 kg base runner begins his slide into second base while moving at a speed of 4.49 m/s. He slides so that his speed is zero just as he reaches the base. The acceleration of gravity is 9.8 m/s². What is the magnitude of the mechanical energy lost due to friction acting on the run- ner?
Answer:
628 J
Explanation:
ME = PE + KE
PE = mgh = 0, because h = 0
KEi (initial KE) = 1/2mv² = 1/2(62.3 kg)(4.49 m/s)² = 628 J
KEf (final KE) = 0, because v-final = 0
All the initial ME, which is all KE, converts to thermal E due to friction
Which model below describes the processes of Gamma radiation?
A
B.
C.
D.
Answer:
C
Explanation:
Ball A with a mass of 0.280kg makes an elastic head-on collision with ball B initially at rest. After collision, ball B moves off with half the original speed of ball A. Is the momentum conserved in the collision? Why?
The mass of ball B and the final velocity of ball A can complement the conservation of linear momentum. The answer is yes.
What is Momentum ?Momentum can simply be defined as the product of mass and velocity. It is a vector quantity.
Given that ball A with a mass of 0.280kg makes an elastic head-on collision with ball B initially at rest. After collision, ball B moves off with half the original speed of ball A.
In an elastic head-on collision, momentum is mostly always conserved. That is, the sum of the momentum before collision will be equal to the sum of the momentum after collision.
Mathematically, MaUa = MaVa + MbVb
Is the momentum conserved in the collision?
The answer is yes!
Why?
Because we need to consider the mass of the ball B and the final velocity of the ball A.
Therefore, In consideration of the mass of the ball B and the final velocity of the ball A, we can say that the momentum is conserved.
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The quasar that appears the brightest in our sky, 3C 273, is located at a distance of 2.4 billion lightyears. The Sun would have to be viewed from a distance of 1300 light-years to have the same apparent magnitude as 3C 273. Using the inverse square law for light, estimate the luminosity of 3C 273 in solar units.
Answer:
Explanation:
Let the luminosity of the star be I and luminosity of the sun be Isun.
2.4 billion light years = 2.4 x 10⁹ light years .
brightness = luminosity / (distance)²
Given Sun would have to be viewed from a distance of 1300 light-years to have the same apparent magnitude as 3C 273 so
For the sun
brightness = Isun / (1300 light years )²
For star
brightness = I / (2.4 x 10⁹ light years )²
Both these brightness are same
Isun / (1300 light years )² = I / (2.4 x 10⁹ light years )²
I = Isun x (2.4 x 10⁹ light years )² / (1300 light years )²
= Isun x 3.4 x 10¹² .
Why is Dimension important in Physics?
Explanation:
Dimensions help understand how physical amounts are related to their dependence on basic or fundamental volumes, i.e. how the body's dimensions rely on mass, time, length and temperature.
Understanding dimensions is of utmost importance as it helps us in studying the nature of physical quantities mathematically. The basic concept of dimensions is that we can add or subtract only those quantities which have same dimensions. Also, two physical quantities are equal if they have same dimensions.
I need help i don’t want to go to summer school
n experimental vehicle starts from rest (0 = 0) at = 0 and accelerates at a rate given by
= (7m/s
3
). What is (a) its velocity and (2) its displacement 2 later?
The velocity of the experimental vehicle after 2 seconds is 14 m/s.
The displacement of the experimental vehicle after 2 seconds is 14 m.
What is the velocity and displacement of the experimental vehicle?The velocity of the experimental vehicle is the speed of the in a given direction starting from rest.
The velocity, v, of the experimental vehicle after 2 seconds is calculated using the formula below:
v = u + at
where;
u is the initial velocity = 0 m/s
a is the acceleration = 7 m/s²
t is time = 2 seconds
v = 0 + 7 * 2
v = 14 m/s
The displacement, s, of the vehicle is calculated below as follows:
v² = u² + 2as
14² = 0² + 2 * 7 * s
s = 196 / 14
s = 14 m
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the work a force does is measured in?
Answer:
newtons
Explanation:
In the metric system of units, where force is measured in newtons (abbreviated N), work is measured in newton-meters (N-m). For reference, a newton is roughly equal to the force exerted on your hand by a baseball.
Answer:
newtons
In the metric system of units, where force is measured in newtons (abbreviated N), work is measured in newton-meters (N-m). For reference, a newton is roughly equal to the force exerted on your hand by a baseball.
A lawnmower is pushed with a force of 72 Newtons at an angle of 40 degrees from the horizontal. How much work is done to the mower if it moves 740 meters?
The work done to the mower is the product of force and the distance covered by the object which is equal to 40,811 Joules.
What is Work done?Work done can be defined as the product of external force and the distance over which the force is being applied. Work is done on an object when a force is applied to an object and the object is moved through a particular distance.
From this we can see that:
X-Component:
cos(θ) = x/F
Then,
X= F cos(θ).…..(1)
Now putting the values of F and θ in equation (1) we get,
X = 72 N × cos(40)
X = 72 N × 0.766
X= 55.15 N this is the x-component force
The work done to the mower is:
W = F × d
W = 55.15 × 740
W = 40,811 Joules
The work done to the mower is 40811 Joules.
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Q12. How big is a Moon? How big is a Mars? What is therefore the weight of the person from Q11 on the Moon? What is the person's weight on Mars?
Answer:
The moon is 1,079.4 mi.
Mars is 2,106.1 mi
Multiply your weight by the moon's gravity relative to earth's, which is 0.165. Solve the equation. In the example, you would obtain the product 22.28 lbs. So a person weighing 135 pounds on Earth would weigh just over 22 pounds on the moon
Being that Mars has a gravitational force of 3.711m/s2, we multiply the object's mass by this quanitity to calculate an object's weight on mars. So an object or person on Mars would weigh 37.83% its weight on earth.
Explanation:
~Hope this helps
A ray of light has a wavelength of
284 nm in glass (n = 1.51). What
is its wavelength in a vacuum?
Answer:
The wavelength in vacuum is equal to 428.8 nm.
Explanation:
Given that,
The wavelength of light, [tex]\lambda=284\ nm[/tex]
The refractive index of glass, n = 1.51
We need to find the wavelength in vacuum. The relation between wavelength and refractive index is given by :
[tex]n=\dfrac{\lambda_v}{\lambda}\\\\\lambda_v=n\times \lambda\\\\\lambda_v=1.51\times 284\\\\\lambda_v=428.8\ nm[/tex]
So, the wavelength in vacuum is equal to 428.8 nm.
the valu
In an experiment the value of thickness of a
wire was found to be 1.54, 1.53, 1.44, 1.54, 1.56
and 1.45 in successive measurements. Then the
percentage error is
(1) 28%
(2).09 %
(3) 9%
(4) 2.8%
Answer:
[tex]\% Error = 2.6\%[/tex]
Explanation:
Given
[tex]x: 1.54, 1.53, 1.44, 1.54, 1.56, 1.45[/tex]
Required
Determine the percentage error
First, we calculate the mean
[tex]\bar x = \frac{\sum x}{n}[/tex]
This gives:
[tex]\bar x = \frac{1.54+ 1.53+ 1.44+ 1.54+ 1.56+ 1.45}{6}[/tex]
[tex]\bar x = \frac{9.06}{6}[/tex]
[tex]\bar x = 1.51[/tex]
Next, calculate the mean absolute error (E)
[tex]|E| = \sqrt{\frac{1}{6}\sum(x - \bar x)^2}[/tex]
This gives:
[tex]|E| = \sqrt{\frac{1}{6}*[(1.54 - 1.51)^2 +(1.53- 1.51)^2 +.... +(1.45- 1.51)^2]}[/tex]
[tex]|E| = \sqrt{\frac{1}{6}*0.0132}[/tex]
[tex]|E| = \sqrt{0.0022}[/tex]
[tex]|E| = 0.04[/tex]
Next, calculate the relative error (R)
[tex]R = \frac{|E|}{\bar x}[/tex]
[tex]R = \frac{0.04}{1.51}[/tex]
[tex]R = 0.026[/tex]
Lastly, the percentage error is calculated as:
[tex]\% Error = R * 100\%[/tex]
[tex]\% Error = 0.026 * 100\%[/tex]
[tex]\% Error = 2.6\%[/tex]
While skiing in Jackson, Wyoming, your friend Ben (of mass 63.2 kg) started his de- scent down the bunny run. 11.5 m above the bottom of the run. If he started at rest and converted all of his gravitational potential energy into kinetic energy, what is Ben's kinetic energy at the bottom of the bunny run? Use g = 9.8 m/s Answer in units of J.
Answer:
Approximately [tex]7.1 \times 10^{3}\; {\rm J}[/tex] (given: [tex]g = 9.8\; {\rm m\cdot s^{-2}}[/tex].)
Explanation:
To find the change in the gravitational potential energy ([tex]\text{GPE}[/tex]), use the formula:
[tex]\begin{aligned}& (\text{change in GPE}) \\ &= (\text{mass})\, (g)\, (\text{change in height})\end{aligned}[/tex].
Assume that gravitational field strength [tex]g[/tex] is constant (e.g., [tex]g = 9.8\; {\rm m\cdot s^{-2}}[/tex].) For an object of mass [tex]m[/tex], if the altitude of the object changes by [tex]\Delta h[/tex], the [tex]\text{GPE}[/tex] of that object would change by [tex]m\, g\, \Delta h[/tex].
In this question, the mass of Ben is [tex]m = 63.2\; {\rm kg}[/tex]. It is given that [tex]g = 9.8\; {\rm m\cdot s^{-2}} = 9.8\; {\rm N\cdot kg^{-1}}[/tex] and is constant. Since change in the altitude of Ben is [tex]\Delta h = 11.5\; {\rm m}[/tex], the change in the ([tex]\text{GPE}[/tex]) of Ben would be:
[tex]\begin{aligned} m\, g\, \Delta h &= (63.2\; {\rm kg}) \, (9.8\; {\rm N\cdot kg^{-1}})\, (11.5\; {\rm m}) \\ &\approx 7.1\times 10^{3}\; {\rm N\cdot m} = 7.1\times 10^{3}\; {\rm J} \end{aligned}[/tex].
Tritium, the 3H atom, consists of a nucleus of one proton and two neutrons with a single electron. It is unstable and decays via beta emission to singly ionized helium, 3 He , consisting of a nucleus of two protons and one neutron with a single electron. This decay takes place instantaneously and thus there occurs a sudden doubling of the Coulomb interaction between the atomic electron and the nucleus. If the tritium atom is in its ground state when it decays, determine the probability that the 3He atom is in its ground state immediately after the decay.
Required:
Determine the probability that the 3H^+ atom is in its ground state immediately after decay.
Answer: hello your question is poorly written attached below is the complete question
P( ³₂He₊ ) at ground state = 1
Explanation:
Determine the probability that the 3He atom is in its ground state after decay
From the attached solution the coulomb interaction of ( ³₂He) is double that of H³ . given that coulomb interaction is attractive ( -ve ) this will make the product to become more stable hence the product ( ³₂He₊ ) will be gotten at the ground state
i.e. P( ³₂He₊ ) at ground state = 1
attached below is a detailed solution
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Which has more momentum, a 0.5kg toy car moving a 5 m/s or a 1000kg real car that is
parked?
Answer:
The toy car. An object that isn't moving has no momentum
Explanation:
Hi, can anyone help me with this question I have?
Assume a tornado is in the vicinity of your neighborhood. Which would
be the most useful information to determine your safety - speed or
velocity? Explain your answer.
Answer:
speed
Explanation:
you need to move fast so the tornado can't reach you
which of the following changes will increase the period of an oscillating spring mass system?
a. an increase in the mass on the spring.
b. an increase in the initial displacement of the spring. c. an increase in the spring constant.
d. more than one of the above.
e. none of the above.
explain your answer.
NO LINKS.
Answer:
a. an increase in the mass on the spring.
Explanation:
An increase in the mass on the spring will increase the period of an oscillating spring mass system.
Mathematically, the period of an oscillating spring mass system is given by the formula;
T = 2π √(m/k)
Where;
T is the period.
m is the mass of the spring.
k is the spring constant.
Hence, the mass of a spring is directly proportional to the period of oscillation of the spring.
This ultimately implies that, as the mass of the spring increases, the period of oscillation will increase. Similarly, the period of oscillation will decrease with an increase in the spring constant i.e there exist an inverse relationship between the period and spring constant.
If 12 coulombs of electric charge pass a point in 4.0
seconds, the current is
A) 8.0 amperes
B) 16 amperes
C) 3.0 amperes
D) 48 amperes
Answer:
AS
Explanation:
Which increases the rate of soil formation?
A. mixed layers
B. more precipitation
C. cooler temperatures
D. very hard parent material
Answer:
a
Explanation:
Answer: b. more precipitation
Explanation:
Someone please help me with this question
How are mass and weight different?
Answer:
The mass is the amount of matter in something. Weight is mass times gravitational field strength and so also includes gravity. Mass is measured in grams (g) and weight is measured in Newtons (N)
Please help help help !!!!! ( science) is
Answer:
I believe it's applied force (push)
Which are dangerous places to put a flammable substance? Check all that apply.
near a flame
on a scale
near a ruler
in a sink
near a hot plate
Answer:
near a flame and a hot plate
Explanation:
A sign which weighs 38.3 N is supported symmetrically by two cables which make an angle of 1.0 degrees with the horziontal. A single cable will pull upward on the sign with a force of how may Newtons?
The single cable will pull upward on the sign with a force of 38.3 N.
What is single cable?Single cable is a type of cable that is composed of a single electrical conductor. It is most commonly used in low voltage applications such as wiring for computers and domestic appliances. Single cable is typically insulated with rubber, PVC or other insulating materials. The insulator protects the conductor from short circuits and other electrical hazards.
This is because the sign is supported symmetrically by two cables, which means that the total downward force on the sign is equal to the total upward force. Since the two cables make an angle of 1.0 degrees with the horizontal, the total downward force on the sign is equal to the combined weight of the sign (38.3 N) and the two cables pulling down on it. Therefore, the single cable must pull up with a force of 38.3 N in order to keep the sign in equilibrium.
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An electron accelerates through a 12.5 V potential difference, starting from rest, and then collides with a hydrogen atom, exciting the atom to the highest energy level allowed. List all the possible quantum-jump transitions by which the excited atom could emit a photon and the wavelength (in nm) of each.
Answer:
Explanation:
An electron accelerates through a 12.5 V potential difference, starting from rest, so it will acquire kinetic energy of 12.5 eV .
In hydrogen atom energy of n th orbit in terms of eV is given as follows
En = -13.6 / n² eV
Total energy of 1 st orbit E₁ = - 13.6 eV
Total energy of 2 st orbit E₂ = - 13.6 eV / 2² = - 3.4 eV
Total energy of 3 st orbit E₃ = - 13.6 eV / 3² = - 1.5 eV
Total energy of 4 st orbit E₄ = - 13.6 eV / 4² = - 0.85 eV
E₄ - E₁ = 13.6 - 0.85 = 12.75 eV
E₃ - E₁ = 13.6 - 1.5 = 12.10 eV
E₂ - E₁ = 13.6 - 3.4 = 10.2 eV .
The electron has energy of 12,5 eV so it can excite electron from E₁ to E₃ . .
Jump possible = E₃ to E₂ , E₂ to E₁ and E₃ to E₁
Energy of E₃ to E₂ = 3.4 - 1.5 eV = 1.9 eV
wavelength = 1237 / 1.9 nm = 651 nm
E₃ - E₁ = 13.6 - 1.5 = 12.10 eV
wavelength = 1237 / 12.10 nm = 102.23 nm
E₂ - E₁ = 13.6 - 3.4 = 10.2 eV
wavelength = 1237 / 10.2 nm = 121.27 nm
wavelength of photon possible are 651 nm , 121.27 nm , 102.23 nm .
Explained Kepler's laws, satellites motion and weightlessness
Which statement can be made about the amplitude of any transverse wave?
It is the length from the midpoint to the crest.
It is half the length from the midpoint to the trough.
It is the length of the wavelength.
It is half the length of the wavelength.
Answer:
A) It is the length from the midpoint to the crest.
Explanation:
The correct statement about the amplitude of any transverse wave is: It is the length from the midpoint to the crest. The correct option is A.
What is a transverse wave?A transverse wave is a type of wave in which the displacement of the medium is perpendicular to the direction of wave propagation.
Examples of transverse waves include light waves and water waves in which the surface of the water oscillates up and down while the wave moves horizontally.
The properties of a transverse wave include:
Amplitude: The maximum displacement of the medium from its rest position. This represents the intensity or strength of the wave.
Wavelength: The distance between two adjacent points in the wave that are in phase with each other, for example, between two consecutive crests or troughs. It is typically represented by the symbol λ.
Frequency: The number of complete wave cycles that pass a point in a given amount of time, usually measured in hertz (Hz). The frequency is inversely proportional to the wavelength and is represented by the symbol f.
Period: The time taken for one complete wave cycle to pass a given point, usually represented by the symbol T. The period is directly proportional to the wavelength and inversely proportional to the frequency.
Speed: The speed at which the wave propagates through the medium, usually represented by the symbol v. The speed is directly proportional to the frequency and wavelength.
These properties are related to each other by the wave equation:
v = fλ,
Where v = the speed of the wave,
f = the frequency,
and λ = the wavelength.
Therefore, The correct statement about the amplitude of any transverse wave is A. It is the length from the midpoint to the crest.
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A ruler partially hangs over the end of a bench. It is supported at one end and made to vibrate at the other end in an attempt to display simple harmonic motion. If the ruler has an amplitude of 0.22 cm and makes twelve complete vibrations in 0.12 seconds, how far does the end of the ruler travel in 4.7 seconds?