Answer:
diverging lens
Explanation:
Since the nature of the problem of nearsightedness is that the light is focused in front of the retina, a diverging lens will serve to diverge light before it reaches the eye. This light will then be converged by the cornea and lens to produce an image on the retina.
If you lie on the ground at night with no cover, you get cold rather quickly. Much of this is due to energy loss by radiation. At night in a dry climate, the temperature of the sky can drop to −40∘C. If you are lying on the ground with thin clothing that provides little insulation, the surface temperature of your skin and clothes will be about 30∘C. Estimate the net rate at which you body loses energy by radiation to the night sky under these conditions. Hint: What area should we use?
Answer:
301.48 J/s
Explanation:
We are given;
Temperature of the sky dropping to −40∘C: T_o = -40°C = -40 + 273 = 233 K
Temperature of your skin and clothes: T = 30°C = 30 + 273 = 303 K
Body surface area of human body is around 2 m². But here only half of the body is facing the sky, Thus Area is: A = 2/2 = 1 m²
To solve this, we will use the equation for thermal heat transfer known as the Stefan bolt Mann equation.
ΔQ/Δt = εσA(T⁴ - (T_o)⁴)
Where;
ΔQ/Δt is the rate at which you body loses energy by radiation
ε is the emissivity of the human body with a value of 0.97
σ is Stefan boltzmann constant with a value of 5.67 X 10^(-8) W/m².K⁴
Thus;
ΔQ/Δt = 0.97 × 5.67 X 10^(-8) × 1(303⁴ - 233⁴)
ΔQ/Δt = 301.48 J/s
A 80 kg parent and a 20 kg child meet at the center of an ice rink. They place their hands together and push. The parent pushes the child with a force of 25 N, what is the force acting on the parent?
Answer:
force acting on the parent = 25 N .
Explanation:
According to third law of Newton , there is equal and opposite reaction to every action . Here force by the parent on child is action and the force by child on parent is reaction . The former is given as 25 N so force by child on parent will also be 25 N .
Answer is 25 N .
a cannon has a mass 2500. it fires a cannon-Ball during a routine exercise. the cannon is 1000 times heavier than the cannon ball. the cannon ball leaves the barrel at a horizontal velocity of 160 m/s. the cannon comes to rest 2 seconds after the cannon ball was fired. calculate the magnitude of average net force that causes the cannon to rest
Answer:
F = 200 [N]
Explanation:
To solve this problem we must use the principle of conservation of linear momentum, which can be calculated by means of the following equation.
[tex]P=m*v[/tex]
where:
P = lineal momentum [kg*m/s]
m = mass [kg]
v = velocity [m/s]
Now we must understand that the momentum is conserved before and after the firing of the cannon. Before firing the cannon we have the mass of the cannon and mass of the cannonball together at rest (speed = 0). After firing the cannon the cannonball moves forward with positive speed, while the cannon moves back (negative), in this way knowing the masses of each one we can determine the speed of the cannon.
[tex](m_{cannon}+m_{ball})*v_{1}=-(m_{cannon}*v_{2})+(m_{ball}*v_{3})[/tex]
where:
m_cannon = 2500 [kg]
m_ball = 2.5 [kg]
v₁ = 0 (velocity of the group before firing)
v₂ = velocity of the cannon after firing [m/s]
v₃ = 160 [m/s] (velocity of the cannonball after firing)
[tex](2500+2.5)*0 = -(2500*v_{2})+(2.5*160)\\v_{2}=0.16[m/s][/tex]
Now using the following equation of kinematics, we can calculate the acceleration.
[tex]v_{f}=v_{o}-a*t[/tex]
where:
Vf = final velocity = 0 (cannon comes to rest)
Vo = initial velocity = 0.16 [m/s]
a = acceleration [m/s²]
t = time = 2 [s]
[tex]0 = 0.16 - a*2\\2*a=0.16\\a = 0.08 [m/s^{2}][/tex]
With the value of acceleration, we can use Newton's second law which tells us that the forces acting on a body is equal to the product of mass by acceleration.
ΣF = m*a
where:
F = force [N] (units of Newtons)
m = mass = 2500 [kg]
a = acceleration = 0.08 [m/s²]
[tex]F = 2500*0.08\\F = 200 [N][/tex]
Please help It is Anatomy and Phys
Think about the last time you had your temperature taken. Describe the circumstances that led you to have your temperature taken, including the mechanism by which your temperature was measured (oral thermometer, ear thermometer, etc.), so that given the right equipment, you could demonstrate the technique yourself to another person. What would have been considered an abnormal temperature in that situation?
Answer:
the last time i had my tempature taken was at disney prings about a week ago -_- they used one of those gun things that dont touch u and the SHOVED me forward so i guess i was fine
Explanation:
Answer:
thermometer
Explanation:
name the force that help us to walk
A 1430 kg is moving at 25.6 m/s when a force is applied, in the direction of the cars motion. The car speeds up to 31.3 m/s. If the force is applied for 5.4 s what is the magnitude of the force
The car accelerates with magnitude a such that
31.3 m/s = 25.6 m/s + a (5.4 s)
→ a = (31.3 m/s - 25.6 m/s) / (5.4 s) ≈ 1.056 m/s²
Then the applied force has a magnitude F of
F = (1430 kg) a ≈ 1500 N
A 2kg block has 70J of KE. It then travels 1.5 meters up a hill. As it travels up the hill friction does -12J of work on the block. What is the new speed of the block?
Please include an explanation.
Answer:
v = 5.34[m/s]
Explanation:
In order to solve this problem, we must use the theorem of work and energy conservation. This theorem tells us that the sum of the mechanical energy in the initial state plus the work on or performed by a body must be equal to the mechanical energy in the final state.
Mechanical energy is defined as the sum of energies, kinetic, potential, and elastic.
E₁ = mechanical energy at initial state [J]
[tex]E_{1}=E_{pot}+E_{kin}+E_{elas}\\[/tex]
In the initial state, we only have kinetic energy, potential energy is not had since the reference point is taken below 1.5[m], and the reference point is taken as potential energy equal to zero.
In the final state, you have kinetic energy and potential since the car has climbed 1.5[m] of the hill. Elastic energy is not available since there are no springs.
E₂ = mechanical energy at final state [J]
[tex]E_{2}=E_{kin}+E_{pot}[/tex]
Now we can use the first statement to get the first equation:
[tex]E_{1}+W_{1-2}=E_{2}[/tex]
where:
W₁₋₂ = work from the state 1 to 2.
[tex]E_{k}=\frac{1}{2} *m*v^{2} \\[/tex]
[tex]E_{pot}=m*g*h[/tex]
where:
h = elevation = 1.5 [m]
g = gravity acceleration = 9.81 [m/s²]
[tex]70 - 12 = \frac{1}{2}*2*v^{2}+2*9.81*1.5[/tex]
[tex]58 = v^{2} +29.43\\v^{2} =28.57\\v=\sqrt{28.57}\\v=5.34[m/s][/tex]
If the magnitude of the electric field of an electromagnetic wave is 3x10^3 V/m, what is the the magntude of the magnetic field?
a. 1.1 x 10^-12 T
b. 9 x 10^11 T
c. 10^5 T
d. 10^-5 T
e. 3 x 10^3 T
Answer:
The value of the magnetic field is [tex]B = 1.0*10^{-5} \ T[/tex]
The correct option is d
Explanation:
From the question we are told that
The magnitude of the electric field is [tex]E = 3*10^{3} \ V/m[/tex]
Generally the magnitude of the magnetic field is mathematically represented as
[tex]B = \frac{E}{c}[/tex]
Here c is the speed of light [tex]c = 3.0*10^{8} \ m/s[/tex]
=> [tex]B = \frac{E}{c}[/tex]
=> [tex]B = \frac{3.0*10^{3}}{ 3.0*10^{8}}[/tex]
=> [tex]B = 1.0*10^{-5} \ T[/tex]
Please help
1. Who was Ptolemy and Copernicus?
2. Describe their ideas about the planets and the sun
Answer:
1 +2=3 so thats it
Explanation:
Because i need points
A disk with a rotational inertia of 2.0 kg m2 and a radius of 1.6 m is free to rotate about a frictionless axis perpendicular to the disk's face and passing through its center. A force of 5.0 N is applied tangentially to the rim of the disk. What is the angular acceleration of the disk as a result of this applied force?
a) 4.0 rad/s2
b) 1.0 rad/s2
c) 2.0 rad/s2
d) 0.40 rad/s2
e) 0.80 rad/s2
Answer:
a) 4.0 rad/s2
Explanation:
For rigid bodies, Newton's 2nd law becomes :τ = I * α (1)
where τ is the net external torque applied, I is the rotational inertia
of the body with respect to the axis of rotation, and α is the angular
acceleration caused by the torque.
At the same time, we can apply the definition of torque to the left side of (1), as follows:[tex]\tau = F*r*sin \theta (2)[/tex]
where τ = external net torque applied by Fnet, r is the distance
between the axis of rotation and the line of Fnet, and θ is the
angle between both vectors.
In this particular case, as Fnet is applied tangentially to the disk, Fnet
and r are perpendicular each other.
Since left sides of (1) and (2) are equal each other, right sides are equal too, so we can solve for the angular acceleration as follows:[tex]\alpha = \frac{F*r}{I} = \frac{5.0N*1.6m}{2.0 kg*m2} = 4.0 rad/s2 (3)[/tex]
one newton equals 0.225
The 20 oz orange soda you drank at lunch contained 1 oz. Of real orange juice. What percent of the orange soda is real orange juice?
When water freezes, its volume increases by 9.05% (that is, equation). What force per unit area is water capable of exerting on a container when it freezes?
Answer:
1.991 × 10^(8) N/m²
Explanation:
We are told that its volume increases by 9.05%.
Thus; (ΔV/V_o) = 9.05% = 0.0905
To find the force per unit area which is also pressure, we will use bulk modulus formula;
B = Δp(V_o/ΔV)
Making Δp the subject gives;
Δp = B(ΔV/V_o)
Now, B is bulk modulus of water with a value of 2.2 × 10^(9) N/m²
Thus;
Δp = 2.2 × 10^(9)[0.0905]
Δp = 1.991 × 10^(8) N/m²
As the building collapses, the volume of air inside the building decreases, while the mass of the air stays the same. This means that the _____ of the air inside the building will increase.
Answer:
Density
Explanation:
The mass and coordinates of three objects are given below: m1 = 6.0 kg at (0.0, 0.0) m, m2 = 1.5 kg at (0.0, 4.1) m, and m3 = 4.0 kg at (1.9, 0.0) m. Determine where we should place a fourth object with a mass m4 = 7.9 kg so that the center of gravity of the four-object arrangement will be at (0.0, 0.0) m
Answer:
The location of the center of gravity of the fourth mass is [tex]\vec r_{4} = (-0.961\,m,-0.779\,m)[/tex].
Explanation:
Vectorially speaking, the center of gravity with respect to origin ([tex]\vec r_{cg}[/tex]), measured in meters, is defined by the following formula:
[tex]\vec r_{cg} = \frac{m_{1}\cdot \vec r_{1}+m_{2}\cdot \vec r_{2}+m_{3}\cdot \vec r_{3}+m_{4}\cdot \vec r_{4}}{m_{1}+m_{2}+m_{3}+m_{4}}[/tex] (1)
Where:
[tex]m_{1}[/tex], [tex]m_{2}[/tex], [tex]m_{3}[/tex], [tex]m_{4}[/tex] - Masses of the objects, measured in kilograms.
[tex]\vec r_{1}[/tex], [tex]\vec r_{2}[/tex], [tex]\vec r_{3}[/tex], [tex]\vec r_{4}[/tex] - Location of the center of mass of each object with respect to origin, measured in meters.
If we know that [tex]\vec r_{cg} = (0,0)\,[m][/tex], [tex]\vec r_{1} = (0,0)\,[m][/tex], [tex]\vec r_{2} = (0, 4.1)\,[m][/tex], [tex]\vec r_{3} = (1.9,0.0)\,[m][/tex], [tex]m_{1} = 6\,kg[/tex], [tex]m_{2} = 1.5\,kg[/tex], [tex]m_{3} = 4\,kg[/tex] and [tex]m_{4} = 7.9\,kg[/tex], then the equation is reduced into this:
[tex](0,0) = \frac{(6\,kg)\cdot (0,0)\,[m]+(1.5\,kg)\cdot (0,4.1)\,[m]+(4.0\,kg)\cdot (1.9,0)\,[m]+(7.9\,kg)\cdot \vec r_{4}}{6\,kg+1.5\,kg+4\,kg+7.9\,kg}[/tex]
[tex](6\,kg)\cdot (0,0)\,[m]+(1.5\,kg)\cdot (0,4.1)\,[m]+(4\,kg)\cdot (1.9,0)\,[m]+(7.9\,kg)\cdot \vec r_{4} = (0,0)\,[kg\cdot m][/tex]
[tex](7.9\,kg)\cdot \vec r_{4} = -(6\,kg)\cdot (0,0)\,[m]-(1.5\,kg)\cdot (0,4.1)\,[m]-(4\,kg)\cdot (1.9,0)\,[m][/tex]
[tex]\vec r_{4} = -0.759\cdot (0,0)\,[m]-0.190\cdot (0,4.1)\,[m]-0.506\cdot (1.9,0)\,[m][/tex]
[tex]\vec r_{4} = (0, 0)\,[m] -(0, 0.779)\,[m]-(0.961,0)\,[m][/tex]
[tex]\vec r_{4} = (-0.961\,m,-0.779\,m)[/tex]
The location of the center of gravity of the fourth mass is [tex]\vec r_{4} = (-0.961\,m,-0.779\,m)[/tex].
A 1369.4 kg car is traveling at 28.9 m/s when the driver takes his foot off the gas pedal. It takes 5.1 s for the car to slow down to 20 m/s. How large is the net force slowing the car
Answer:
F = 2389.603 N
Explanation:
Given:
Mass m = 1,369.4 kg
Initial velocity u = 28.9 m/s
Final velocity v = 20 m/s
Time t = 5.1 s
Find:
Net force
Computation:
a = (v - u)/t
a = (20 - 28.9)/5.1
a = -1.745 m/s²
F = ma
F = (1369.4)(1.745)
F = 2389.603 N
According to the law of conservation of momentum, in an isolated system:
A. The initial and final velocities remain the same.
B. The total initial momentum is equal to the total final momentum.
C. One of the colliding objects must be at rest.
D. The final momentum is always less than the initial momentum.
Answer:
Explanation:B
Which two things occur when electric charges move through a conductor?
A. The field is perpendicular to the electron flow.
B. The field is parallel to the electron flow.
C. An electric field forms.
D. A magnetic field forms.
The two correct answers are A and D ap3x approved!
A C and D
C because ofc when electric charge flow electric field is produced
Answer:
A & D
Explanation:
What causes Ep to be converted to Ek? (giving brainliest to right anwser)
Answer:
Energy is a quantity that can be verticality from one to another,
sum of all the energy of the system remains constant if there is no friction force.
Explanation:
The potential energy of a system is a configuration energy, that is, for a given position the energy has a value with respect to a reference point.
Kinetic energy is an energy related to the movement of bodies, that is, a body must have a speed to have kinetic energy.
Energy is a quantity that can be verticality from one to another, the gravitational potential that a body has at a given height when the body is released accelerates by action of gravity, in this case the potential energy decreases and the scientific energy increases, It is appropriate to clarify that the sum of all the energy of the system remains constant if there is no friction force.
A person standing a certain distance from four identical loudspeakers is hearing a sound level intensity of 125 dB. What sound level intensity would this person hear if all but one are turned off?
Answer:
[tex]\mathbf{\beta = 123.75 \ dB}[/tex]
Explanation:
From the question, using the expression:
[tex]125 \ dB = 10 \ log (\dfrac{I}{I_o})[/tex]
where;
[tex]I_o = 10^{-12} \ W/m^2[/tex]
[tex]I = 10^{12.5} \times 10^{-12} \ W/m^2[/tex]
[tex]I = 3.162 \ W/m^2[/tex]
This is a combined intensity of 4 speakers.
Thus, the intensity of 3 speakers = [tex]\dfrac{3.162\times 3}{4}[/tex]
= 2.372 W/m²
Thus;
[tex]\beta = 10 \ log ( \dfrac{2.372}{10^{-12}} ) \ W/m^2[/tex]
[tex]\mathbf{\beta = 123.75 \ dB}[/tex]
What would its weight be on Jupiter?
24.9N
Answer:
1.898 × 10^27 kg
Explanation:
thats how much it ways
What is the atomic number for the following Bohr model?
e
P= 8
N= 8
---
a
8
b
2
OOOO
с
6
d
16
Answer:
8
Explanation:
Atomic number in the Bohr model given is 8.
For every atom, the atomic number is the number of protons in such an atom.
The protons are the positively charged particles found in an atom. They are called the atomic number.
Protons are found in the nucleus of an atom. Together with neutrons, the occupy the tiny nucleus of the atom. By so doing and coupled with their mass, the form the mass of atom. The atomic number is used to identify every atom.. A horizontal steel spring has a spring constant of 40.0 N/m. What force must be applied to the spring in order to compress it by 10.0 cm?
Ans 4 more to be exact
Explanation:
Given values are:
Spring constant,
k = 40 N/mand,
x = 10 mThe force will be:
→ [tex]F = kx[/tex]
By substituting the values, we get
[tex]= 40\times 10[/tex]
[tex]= 400 \ N[/tex]
Thus the above answer is right.
Learn more about spring constant here:
https://brainly.com/question/15277652
How much power is required to carry a 30 N package a vertical distance of 8 m if the work on the package is accomplished in 15 s?
58 W
630 W
21 W
16 W
Answer:
poop bear cookie
Explanation:
How does opening a parachute slow the fall rate of a skydiver?
Answer:
the air is being stopped in the pocket of the parachutes theys why the parachute has a certain shape so that the air that gets caught inside of it as the skydiver goes down slows down the landing
Justify this statement "Density of the impure water is greater than of pure water.
Explaining the concept:
To explain this, we first need to know what density actually is:
Density is the mass of a given substance per unit volume, which means, that is the amount of mass present in unit volume (1 cm³ , 1m³)
Impure water is water, but with impurities added to it
Why is the density of Impure water is greater:
When we compare the mass of equal volumes of Water and Impure water, we will find that the mass of Impure water will be more, that is because the extra mass is of the impurities
Since impure water has impurities uniformly spread in it, we will find more matter in unit volume of Impure water than in Pure water
That is why the density of Impure water is greater
The force of gravity between any two ordinary objects on the earth is.......
A) stronger when closer to the earth
B) stronger if the objects are closer to each other C) always downward
D) stronger than the force of gravity from the earth
Answer:
c
Explanation: beacuse newtons law of phisics says ''what goes up must come down''
The force of gravity between any two ordinary objects on the earth is stronger if the objects are closer to each other.
The force of gravity between two object on the earth surface is given Newton's law of universal gravitation;
[tex]F= \frac{Gm_1m_2}{r^2}[/tex]
where;
G is gravitational constantm₁ and m₂ are the masses of the two objectsr is the distance between the two objectsThe distance between the object is inversely proportional to the force of gravity between the objects. The smaller the distance between the two objects, the greater the force of gravity and vice versa.
Thus, we can conclude that the force of gravity between any two ordinary objects on the earth is stronger if the objects are closer to each other.
Learn more here:https://brainly.com/question/10609143
E=6.63E-34J-s*4.6E14 hz
A circuit component that is a composed of a semiconductor layer sandwiched between two other semiconductor layers is a(n)?
Explanation:
It's a transistor. Hope that helps!
Answer:
D. Transistor
Explanation:
Edge 2021
When you heat water on a stove, how does its energy change?
A. Its electromagnetic energy decreases.
B. Its thermal energy decreases. c. Its thermal energy increases.
D. Its electromagnetic energy increases.
Answer:
C. its thermal energy increases
Answer:
Explanation:
C