Answer:
a) p = 95.66 cm, b) p = 93.13 cm
Explanation:
For this problem we use the constructor equation
[tex]\frac{1}{f} = \frac{1}{p} + \frac{1}{q}[/tex]
where f is the focal length, p and q are the distances to the object and the image, respectively
the power of the lens is
P = 1 / f
f = 1 / P
f = 1 / 2.25
f = 0.4444 m
the distance to the object is
[tex]\frac{1}{p} = \frac{1}{f} -\frac{1}{q}[/tex]
the distance to the image is
q = 85 -2
q = 83 cm
we must have all the magnitudes in the same units
f = 0.4444 m = 44.44 cm
we calculate
[tex]\frac{1}{p} = \frac{1}{44.44} - \frac{1}{83}[/tex]
1 / p = 0.010454
p = 95.66 cm
b) if they were contact lenses
q = 85 cm
[tex]\frac{1}{p} = \frac{1}{44.44} - \frac{1}{85}[/tex]
1 / p = 0.107375
p = 93.13 cm
A bullet fired vertically at a velocity of 36m/s .after 45 the bullet hit the top of a bulid how height is a bulid?
Answer:
The height of the building is 8,302.5 m
Explanation:
Given;
velocity of the projectile, u = 36 m/s
time of motion, t = 45 s
Let the upward direction of the bullet be negative,
The height of the building is calculated as;
[tex]h = ut - \frac{1}{2} gt^2\\\\h = (36\times 45) - (\frac{1}{2} \times 9.8 \times 45^2)\\\\h = 1620 - 9922.5\\\\h = -8,302.5 \ m\\\\The \ height \ of \ the \ building \ is \ 8,302.5 \ m[/tex]
A boy is playing with a water hose, which has an exit area of
10 cm2 and has water flowing at a rate of 2 m/s. If he covers
the opening of the hose with his thumb so that it now has an
open area of 2 cm2, what will be the new exit velocity of the
water?
Answer:
The exit velocity of water is B. 15 m/s.
Explanation:
According to equation of continuity, for a steady flow of water, the volume of liquid entering a pipe in 1 second is equal to the volume that leaves per second.
If the initial exit area of the pipe is A₁ and the speed of exit is v₁ and the final exit area is A₂ and its corresponding exit velocity is v₂, then,
Rewrite the expression for v₂.
Substitute 10 cm² for A₁, 2 cm² for A₂ and 3 m/s for v₁.
The exit speed of water from the hose is 15 m/s.
Upon completing an interview, it is important that you send a follow-up thank you
note/letter/e-mail because it will show that you are a person who appreciates an opportunity.
A True
B
False
the speed of the pulse depends on what?
Answer:
The pulse speed depends on the properties of the medium and not on the amplitude or pulse length of the pulse.
Explanation:
Hope this helps.
Magnetic field lines begin at the _?_ pole of a magnet and end at the _?_ pole
Two objects are interacting, but stay stationary. Which best describes what is happening to the action and react
forces?
There are no forces acting on the objects.
The forces are equal and opposite each other.
One object is exerting more force than the other.
O Their forces are occurring at different times.
Answer:b the force are equal and opposite each other
Explanation:
g As they reach higher temperatures, most semiconductors... Selected Answer: have an increased resistance. Answers: have a constant resistance. have an increased resistance. have a decreased resistance.
Answer:
have an increased resistance
Determine the absolute pressure on the bottom of a swimming pool 27.0 m by 8.9 m whose uniform depth is 1.8 m . Express your answer using two significant figures.
Answer:
[tex]P=17658Pa[/tex]
Explanation:
From the question we are told that:
Dimension
[tex]L*B=27.0*8.9[/tex]
Depth [tex]d=1.8m[/tex]
Generally the equation for Volume of water is mathematically given by
[tex]V=L*B*D[/tex]
[tex]V=27.0*8.9*1.8[/tex]
[tex]V=432.54m^3[/tex]
Therefore
Force at the bottom of the Pool
[tex]F=\rho Vg[/tex]
Where
[tex]\rho \ density\ of \ water(1000kg/m^3)[/tex]
[tex]F=1000*432.54m^3*9.81[/tex]
[tex]F=4.2*10^{6}N[/tex]
Generally the equation for Pressure at the bottom is mathematically given by
[tex]P=\frac{Forece }{Area}[/tex]
[tex]P=\frac{4.2*10^{6}N}{27.0*8.9}[/tex]
[tex]P=17658Pa[/tex]
Explain whether the unit of work is a fundamental or derived unit
Answer:
answer here
Explanation:
the unit of work is fundamental unit because it doesn't depend on other units.
__________________
Thx
Answer:
The SI unit of work is joule (J)
Explanation:
Joule is a derived unit. ∴ unit of work is a derived unit
8. If a moving object triples its speed, how much kinetic energy will it have? A. six times as much as before B. three times as much as before C. one third as much as before D. nine times as much as before
D
Explanation:
KE: 0.5mv²
when v is tripled v² is 9 times its original value
If it requires 8.0 J of work to stretch a particular spring by 2.0 cm from its equilibrium length, how much more work will be required to stretch it an additional 4.0 cm
collisions may take place between
Answer:
Collisions may take place between the reactants.
Explanation:
The collision frequency must be greater than the frequency factor for the reaction. A collision between the reactants must occur.
suppose the tank is open to the atmosphere instead of being closed. how does the pressure vary along
Answer:
Pressure is more in the open container than the closed one.
Explanation:
The pressure due to the fluid at a depth is given by
Pressure = depth x density of fluid x gravity
So, when the container is open, the atmospheric pressure is also add up but when the container is closed only the pressure due to the fluid is there.
So, when the container is open, the pressure is atmospheric pressure + pressure due to the fluid.
hen the container is closed only the pressure due to the fluid is there.
water contracts on freezing is it incorrect or conrrect
Answer:
hope it helps
much as you can
Explain the following observations:
a) A balloon filled with hydrogen gas floats in air;
B) A ship made of steel floats on water.
Answer and Explanation:
a. An oxygen-filled balloon is not able to float in the air, because the oxygen inside the balloon is of the same density, that is, the same "weight" as the oxygen outside the balloon and present in the atmosphere. The balloon can only float if the gas inside it is less dense than atmospheric oxygen. Helium gas is less dense than atmospheric gas, so if a balloon is filled with helium gas, that balloon will be able to float because of the difference in density.
b. The ship is able to float in the water because its steel construction is hollow and full of air. This makes the average density of this ship less than the density of water, which makes the ship lighter than water and for this reason, this ship is able to float. In addition, the ship is partially immersed, allowing the weight of the ship on the water to counteract the buoyant force that the water promotes on the ship. Weight and buoyant are two opposing forces that keep the ship afloat.
Gradual shifting or movement of a time series to relatively higher or lower values over a longer period of time is called _____.
Answer:
Gradual shifting of a time series to relatively higher or lower values over a long period of time is called a Trend.
Question 2 of 10
Which of the following statements is true of an isolated system?
A.The system has energy but no matter.
B.Energy separates the matter in the system from outside matter.
C.The matter within the system does not interact with matter outside the system
D.The matter within the system does not interact with other matter in the system
Answer:
D
Explanation:
because it is system removed from system and it dosent interact with them
Calculate the volume of 10g of helium ( M= 4kg/kmol) at 25C and 600 mmHg
Answer:
T=273+25=298 K
n= m/M = 10/ 4 = 2.5
R=0.08206 L.atm /mol/k
760mmHg = 1 atm therefore
600mmHg = X atm
760 X = 600mmHg
X = 600/760 = 0.789 atm
P = 0.789 atm
V= ?
PV= nRT
0.789 V = 2.5 × 0.08206 × 298
V= 2.5 × 0.08206 ×298 / 0.789
V= 77.48 L
I hope I helped you ^_^
In the following image, atoms are represented by colored circles. Different colors represent different types of atoms. If
atoms are touching, they are bonded.
Which of the following boxes shows a mixture of different compounds?
A
B
C
E
Answer:
Explanation:
There are all kinds of things floating around in B. The large dark blue and the smaller dark blue are one kind of compound.
The yellow by itself could be from column 18.
So could the smaller dark blue circle (be from column 18).
There are Big blue ones that have only 1 small blue one associated with it and others with one Big blue and two smaller light blues.
B is the answer to your question.
A source emits sound at a fixed constant frequency f. If you run towards the source, the frequency you hear is
Answer:
increased because as you run into each sound wave the time between each sound decreases meaning the period of each wave decreases to your years and since f=1/T and T is decreasing by greater than 0, f must increase.
Explanation:
Why does a compass give unreliable readings when used near electrical appliances
Answer:
Explanation:
Since the compass uses a magnetic field, if anything else magnetic is near it, the compass will start acting up. Making it unreliable so keep magnets away!
What best describes a societal law
Answer:
Societal laws are based on the behavior and conduct made by society or government.hope it helps.stay safe healthy and happy.
A student claimed that thermometers are useless because a
thermometer always registers its own temperature. How would you
respond?
[
A proton enters a region of constant magnetic field, perpendicular to the field and after being accelerated from rest by an electric field through an electrical potential difference of 330 V. Determine the magnitude of the magnetic field, if the proton travels in a circular path with a radius of 23 cm.
Answer:
B = 1.1413 10⁻² T
Explanation:
We use energy concepts to calculate the proton velocity
starting point. When entering the electric field
Em₀ = U = q V
final point. Right out of the electric field
em_f = K = ½ m v²
energy is conserved
Em₀ = Em_f
q V = ½ m v²
v = [tex]\sqrt{2qV/m}[/tex]
we calculate
v = [tex]\sqrt{\frac{ 2 \ 1.6 \ 10^{-19} \ 300}{1.67 \ 0^{-27}} }[/tex]
v = [tex]\sqrt{632.3353 \ 10^8}[/tex]
v = 25.15 10⁴ m / s
now enters the region with magnetic field, so it is subjected to a magnetic force
F = m a
the force is
F = q v x B
as the velocity is perpendicular to the magnetic field
F = q v B
acceleration is centripetal
a = v² / r
we substitute
qvB =1/2 m v² / r
B = v[tex]\frac{m v}{2 q r}[/tex]
we calculate
B = [tex]\frac{1.67 \ 10^{-27} 25.15 \ 10^4 }{1.6 \ 10^{-19} 0.23}[/tex]
B = 1.1413 10⁻² T
Shooting a rock with a slingshot converts
energy to__________,
energy____________,
Answer:
converts elastic energy to mechanical energy
Explanation:
A system gains 1500J of heat and 2200J of work is done by the system on its surroundings. Determine the change in internal energy of the system
Answer:
-700
formula is heat gained - work done
The change in internal energy if A system gains 1500J of heat and 2200J of work is done by the system on its surroundings, is 700 joules.
What is Energy?Energy is the ability to perform work in physics. It could exist in several different forms, such as potential, kinetic, thermal, electrical, chemical, radioactive, etc.
Additionally, there is heat and work, which is energy being transferred from one body to another. Energy is always assigned based on its nature once it has been transmitted. Thus, heat transmitted may manifest as thermal energy while work performed may result in mechanical energy.
Given:
A system gains 1500J of heat and 2200J of work is done by the system on its surroundings,
Calculate the change in internal energy as shown below,
The change in internal energy = heat gained - work done
The change in internal energy = 1500 - 2200
The change in internal energy = -700 J
Thus, the change in internal energy is 700 joules.
To know more about Energy:
https://brainly.com/question/8630757
#SPJ5
Receptor elétrico 5 pontos Dispositivo que converte energia elétrica em outra forma de energia, não exclusivamente térmica. Exemplos: motores elétricos, ventiladores, liquidificadores, geladeiras, aparelhos de sons, vídeos, celulares, computadores?
Answer:
Electromechanical transducer and Electrical receiver.
Explanation:
Electromechanical transducer is the part of a communication system which converted electrical waves or electrical energy into sound waves. The most common example loudspeaker while on the other hand, Electrical receiver is a device that converts electrical energy into another form of energy, except thermal. Examples are cell phones, computers and television.
A small plane tows a glider at constant speed and altitude. If the plane does 2.00 * 105 J of work to tow the glider 145 m and the tension in the tow rope is 2560 N, what is the angle between the tow rope and the horizontal
Answer:
θ = 57.4°
Explanation:
The complete formula to find out the work done by the plane is as follows:
[tex]W = FdCos\theta[/tex]
where,
W = Work = 200000 J
F = Force = Tension = 2560 N
d = distance = 145 m
θ = angle between rope and horizontal = ?
Therefore,
[tex]200000\ J = (2560\ N)(145\ m)Cos\theta\\\\Cos\theta = \frac{200000\ J}{371200\ J}\\\\\theta = Cos^{-1}(0.539)[/tex]
θ = 57.4°
A cat's displacement is 15 meters to the right in 7.0 seconds. If, at the start of the 7.0 seconds, the cat was moving at a velocity of 2.0 m/s left what was its final velocity?
Answer:
6.3 m/s
Explanation:
From the given information:
The displacement (x) = 15 m
time (t) = 7.0 s
initial velocity = -2.0 m/s (since it is moving in the opposite direction)
We need to determine the acceleration then find the final velocity.
By applying the kinematics equation:
[tex]x = ut + \dfrac{1}{2}at^2[/tex]
[tex]15 = (-2.0)(7.0) + \dfrac{1}{2}a(7.0)^2\\ \\ 15 = -14.0 + \dfrac{49}{2}a \\ \\ 29= 24.5a \\ \\ a= \dfrac{29}{24.5} \\ \\ a = 1.184 \ m/s^2[/tex]
Now, to determine the final velocity by using the equation:
v = u + at
v = -2 + 1.184(7.0)
v = 6.288 m/s
v ≅ 6.3 m/s
A mass attached to the end of a spring is oscillating with a period of 2.25 s on a horizontal frictionless surface. The mass was released from rest at
t = 0
from the position
x = 0.0480 m.
Determine the location of the mass at
t = 5.85 s?
Answer:
[tex]X=0.0389m[/tex]
Explanation:
From the question we are told that:
Period of spring [tex]T_s=2.25s[/tex]
Initial Position of Mass [tex]x=0.0480m[/tex]
Final Mass period [tex]T_f=5.85s[/tex]
Generally the equation for the Mass location is mathematically given by
[tex]X=xcos*\frac{2\pi T_s}{T_f}[/tex]
[tex]X=0.048*cos*\frac{2\pi 5.85}{2.25}[/tex]
[tex]X=0.0389m[/tex]