7. Telescope efficiency depends on the area of the primary mirror, while angular resolution scales as 1/D, where D is the diameter of the telescope. State which is true concerning the objects observed with a 30m telescope, versus a 10m telescope. A) The 30 m telescope can observe objects 30 times fainter, and with 3 times the resolution of the 10 m telescope. B) The 30 m telescope can observe objects with 1/9 the angular diameter, and 9 times fainter than, the 10 m telescope. C) The 30 m telescope can observe objects 9 times fainter, and with 3 times smaller angular size, than the 10 m telescope. D) The 30 m telescope can observe objects 3 times fainter, and with 3 times smaller angular size, compared to the 10 m telescope.
Answer:
Option C, The 30 m telescope can observe objects 9 times fainter, and with 3 times smaller angular size, than the 10 m telescope.
Explanation:
As we know,
The surface brightness of the object viewed through telescope is proportional to the square of the diameter of the lens
Thus, Brightness ([tex]B_{30}[/tex]) of 30 m telescope would be proportional to [tex]30^2[/tex]
Brightness of 10 m ([tex]B_{10}[/tex]} telescope would be proportional to [tex]10^2[/tex]
Thus, the ration of the two would be
[tex]\frac{B_{30}}{B_{10}} = \frac{30^2}{10^2} \\\frac{B_{30}}{B_{10}} = \frac{9}{1} \\B_{30} = 9 * B_{10}[/tex]
Thus, brightness of 30 m telescope would be able to view 9 times fainter object as compared to the 10 m telescope.
Also , 30 m telescope would be able to view 3 times smaller angular sized object as compared to the 10 m telescope
Hence, option C is correct
According to Hooke's law, the force exerted by a compressed or stretched spring is proportional to...
Answer:
Hooke's law can be written as:
F = -k*Δx
Where k is a constant that depends on the spring, called the spring constant.
And Δx = (x - x₀) is the displacement of the spring with respect to the rest position x₀
And a proportional equation is something like:
y = c*x
Where c is a constant of proportionality.
In the case of Hooke's law, the constant is K, then the force is proportional to the displacement of the spring with respect to the rest position Δx.
A 20.0 Ohm and 60.0 Ohm resistor
are connected in series to a 9.00 V
battery. What is their equivalent
resistance?
(Unit = Ohms)
Answer:
for resistors in series, add the resistances to get their equivalence. The answer is
80.0 Ohms
What is only found in plant cells??
Cell membrane , nucleus, cell wall , vacuole.
which one !!!
Help!!!
Where can the hoses be attached in order to provide water to a fire engine? (There may be more than one correct answer.)
house faucet
hydrant
generator
pumper truck
Answer:
Explanation:
Hydrant
Jack and Jill are pushing a 3 kg object on a rough surface; the object accelerates at a rate of 5 m/s2. Calculate the force applied by the Jack knowing that Jill is pushing 4 N and the rough surface applies 2 N force on the box as friction force.
Answer:
13 N
Explanation:
From the question,
(F₁+F₂)-F' = ma................ Equation 1
Where F₁= Jack's force, F₂ = Jill's force, F' = Friction force, m = mass of the object, a = acceleration of the object.
Given: F₂ = 4 N, F' = 2 N, m = 3 kg, a = 5 m/s²
Substitute these values into equation 1 and solve for F₁
(F₁+4)-2 = 3×5
(F₁+4)-2 = 15
F₁+4 = 15+2
F₁+4 = 17
F₁ = 17-4
F₁ = 13 N
Hence the force applied by Jack is 13 N
Mainly need help with part A. No links, thanks!
Answer:
R = 4Ω
Explanation:
If we have two resistors with resistances R1 and R2 in series the total resistance is R = R1 + R2
If the resistances are in parallel, the total resistance is given by:
1/R = 1/R1 + 1/R2.
First, we have a resistor with R1 = 1.5Ω
This resistor is connected in series with a parallel part (let's find the resistance of this parallel part), in one branch we have two resistors in series with resistances:
R2 = 8Ω and R3 = 4Ω
Because these are in series, the resistance of that branch is:
R = 8Ω + 4Ω = 12Ω
In the other branch, we have a single resistor of R4 = 4Ω
The resistance of the parallel part is:
1/R = 1/12Ω + 1/4Ω = 1/12Ω + 3/12Ω = 4/12Ω = 1/3Ω
1/R = 1/3Ω
R = 3Ω
Then we have a resistor (the first one, R1 = 1.5Ω) in series with a resistor of 3Ω.
Then the total resistance is:
R = 1Ω + 3Ω = 4Ω
A measure of an object's is a measure of the object's inertia.
Answer: Mass is the quantity of matter in an object. More specifically, mass is a measure of the inertia, or “laziness,” that an object exhibits in response to any effort made to start it, stop it, or otherwise change its state of motion. Weight is the force of gravity on an object.
The lens of a telescope has a diameter of 25 cm. You are using it to look at two stars that are 2 × 1017 m away from you and 6 × 109 m from each other. You are measuring light with a wavelength of 700 nm. As the light goes through the lens, it diffracts. a. Is it possible, using this telescope, to see the two stars as separate stars? b. What is the minimum possible lens diameter you would need in order to resolve these two stars?
Answer:
a)It is NOT possible using this telescope, to see the two stars as separate stars
b)[tex]d_{min} =28.466m[/tex]
Explanation:
From the question we are told that:
Diameter of lens,[tex]d = 25 cm \approx 0.25 m[/tex]
Distance from both star [tex]D_f= 2*10^{17} m[/tex]
Distance between both stars [tex]D_b= 6*10^9 m[/tex]
Wavelength of light [tex]\lambda =700 nm \approx 700*10^-9 m[/tex]
Generally the equation for angle subtended by the two stars at the lens is mathematically given by
[tex]\theta=\frac{D_f}{D_b}[/tex]
[tex]\theta=\frac{6*10^9}{2*10^{17}}[/tex]
[tex]\theta=3.0*10^{-8} rad[/tex]
Generally the equation for minimum angular separation of two object is mathematically given by
[tex]\theta_{min} = 1.22*\lambda/d[/tex]
[tex]\theta_{min}= \frac{1.22*700*10^-9}{0.25}[/tex]
[tex]\theta_{min}= 3.416*10^-^6 rad[/tex]
Therefore
[tex]\theta < \theta_{min}[/tex]
[tex]3.0*10^{-8} rad< 3.416*10^-^6 rad[/tex]
It is NOT possible using this telescope, to see the two stars as separate stars
b)
Generally the equation for minimum diameter of the lens is mathematically given by
[tex]d_{min} =\frac{ 1.22*\lambda}{\theta}[/tex]
[tex]d_{min} =\frac{ 1.22*700*10^{-9}}{3*10^{-8}}[/tex]
[tex]d_{min} =28.466m[/tex]
Reo performed an experiment to investigate the strength of an electromagnet and the amount of force that would be affected by the size of the current flowing through its coils. Which of the following changes would increase the current flow the most?
a. Decreasing the number of paper clips being picked up
b. Decreasing the number of coils of wire wrapped around the nail
c. Increasing the voltage power supply
d. Increasing the number of nails
(WILL GIVE BRAINLIEST)
Answer:
b. Decreasing the number of coils of wire wrapped around the nail
it can cause an electrical current running through it creates a magnetic field.
a body falls freely from rest.calculate it's acceleration
Answer:
10 m/s²
Explanation:
Since the body is falling freely from the rest, it will be having an acceleration equal to the acceleration due to gravity.
∴ Acceleration = g = 9.8 m/s². ≈ 10 m/s².
Answer:
10 m/s^2 I hope it helps u a lot
Jim wishes to push a 100. N wood crate across a wood floor.What is the minimum horizontal force that would be required to start the crate moving?
For the wood crate to move, the force applied (minimum horizontal force) must be greater than the static friction between the wood crate and the wood floor
Given that Jim wishes to push a 100. N wood crate across a wood floor.
The weight of the wood = 100N
The weight will produce a normal reaction N which is equal in magnitude to the magnitude of the weight. That is,
N = mg = 100N
For the wood crate to move, the force applied must be greater than the static friction between the wood crate and the wood floor.
Static friction = μN
Where μ = static friction.
Therefore, the minimum horizontal force that would be required to start the crate moving depend on the nature of the surface of the wood floor.
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Differentiate between:
a. Compression and Rarefaction
Answer:
Explanation:
Compression
The region in a medium where the distance between the vibrating molecules is minimum is compression.
This is the region with higher air pressure than the surrounding .
Rarefaction
The region in a medium where the distance between the vibrating molecules is maximum is rarefaction.
This is the region with relatively low air pressure.
hope it helps :)
Does earths Roation causes gravity?
Answer:
he gravity of Earth, denoted by g, is the net acceleration that is imparted to objects due to the combined effect of gravitation (from mass distribution within Earth) and the centrifugal force (from the Earth's rotation )
A drop of oil of volume 10 ^-10 m3 spreads out on water to make a circular film radius 10^-1m what is the thickness of the film
Answer:
The thickness of the film is = 3.183e-9m
Explanation:
It will help us if we understand that the shape of the circular film can be approximated to be a cylinder. The height of this cylinder, or its thickness, in this case, will be very small.
Since we can approximate the shape of the drop of oil to be a cylinder, after it has spread out on the surface of the water, we can use the cylindrical geometric formulas to find out how thick the film is.
The volume of a cylinder = [tex]\pi r^2 h[/tex]
our radius is given as [tex]10^{-1}m = 0.1m[/tex]
the volume is [tex]10 ^{-10} m^3=1e-10m^3[/tex]
Remember that our task is to find the height of the cylinder. We can do this by making the height the subject of the formula.
[tex]h = \frac{Volume}{\pi r^2} = \\\\\frac{1e-10}{\pi \times 0.1^2} = 3.183e-9m[/tex]
Therefore, the thickness of the film is = 3.183e-9m
When a substance is poured from one container to another, its shape changes but its volume does not, what state of matter is the substance in?
A. Plasma
B. Liquid
C. Gas
D. Solid
Answer: When a liquid substance is poured into a vessel, it takes the shape of the vessel, and, as long as the substance stays in the liquid state, it will remain inside the vessel. Furthermore, when a liquid is poured from one vessel to another, it retains its volume (as long as there is no vaporization or change in temperature) but not its shape.
Explanation: A solid has a definite shape and volume. A liquid has a definite volume, but takes the shape of its container. A gas lacks either a defined shape or volume. Plasma is similar to a gas in that its particles are very far apart, but a gas is electrically neutral and plasma has a charge.
Answer:
B
Explanation:
Liquid
A 50,000 kg train is rolling on its own down the track at 5 m/s. You grab the rope trailing behind it, and exert a stopping force of 2000 N. How long does it take to stop the train?
Answer:
t = 125 seconds
Explanation:
Given that,
The mass of a train, m = 50,000 kg
Initial speed, u = 5 m/s
Stopping force, F = 2000 N
We know that,
Force, F = ma
Where
a is acceleration
[tex]F=\dfrac{m(v-u)}{t}\\\\t=\dfrac{m(v-u)}{F}\\\\t=\dfrac{50000(0-5)}{-2000}\\\\t=125\ s[/tex]
So, it will take 125 seconds to stop the car.
When a bouncy ball is dropped from a second floor window, at what point is the kinetic energy highest?
A. Just after the ball dropped
B. Just before the ball hits the ground for the first time
C. After the ball has bounced several time
D. after the ball bounces away into the bushes, never to be found again
Answer:
Explanation:
Because the total energy available to the ball doesn't change whatsoever during its entire trip from the window to the ground,
TE = KE + PE which says that the total energy available to a system is equal to the kinetic energy of the system plus the potential energy, and that this value will not ever change (because energy cannot be created or destroyed. Sound familiar?) If the ball is being held still before it is dropped from some height off the ground, it is here that the total energy can be determined, and that total energy at this point is all potential, since the ball is not moving while someone is holding it and getting ready to drop it. The SECOND it starts to fall, the potential energy begins to be converted to kinetic. As the potential energy is losing value, the kinetic is gaining it at the same rate (again, energy doesn't just disappear; it has to go somewhere. Here, it goes from potential to kinetic a little at a time). When the ball finally hits the ground, or an INSTANT BEFORE it hits the ground, the potential energy is 0 because the height of something on the ground has a height of 0. At this instant, right before the ball hits the ground, is where the KE is the greatest. All the energy at that point has been converted from potential to kinetic.
Long story short, choice B is the one you want.
A 3kg object moving at 4 m/s encounters a 20 N resistive force over a duration of 0.20 seconds. The impulse experienced by this object is _____
Answer:
the impulse experienced by this object is 4 Ns
Explanation:
Given;
mass of the object, m = 3 kg
velocity of the object, v = 4 m/s
resistive force, F = 20 N
duration of impact, t = 0.2 s
The impulse experienced by this object is calculated as follows;
J = F x t
J = 20 x 0.2
J = 4 Ns
Therefore, the impulse experienced by this object is 4 Ns
Using the information provided in the table, which statement BEST describes the object's motion?
Answer:
the velocity is decreasing therefore acceleration is negative
can someone please solve this
Answer:
The gravity is pulling the diver downwards but the rotation of the body means gravity cant pull him down as quickly
Explanation:
Determine the resistance of 100m of copper cable whose cross-sectional area is 1.5mm2
What is density?
A- How much space an object takes
up
B- The amount of matter in a certain
amount of space
C- How much water an object
displaces
D- How much an object is affected by
gravity
Answer:
B- The amount of matter in a certain
amount of space
Explanation:
Density is the amount of matter an object has in a certain space. To find density, divide the mass of an object by the volume of an object.
Answer:
C- How much water it displaces
Explanation:
You slide out of a car seat and as you touch the metal door a spark jumps between your hand and the door. Describe how the spark formed
Answer: Your body sliding against the car seat created friction, making it created potential energy. The friction is a form of electricity, and the car doors metal is a conductor of electricity. That potential energy was turned into kinetic once the metal attracted the electricity, thus making a spark.
Hope this helps ^_^
A cat weighing 7 kg chases a mouse at a speed of 4 m/s. What is the kinetic energy of the cat?
How much work is done when 300 N of force is used to lift the dog 1.5 m?
Answer:
450N
Explanation:
Work done=Force*distance
Suppose a spring compresses by 5cm if you put a 250 gram weight on top of it. How
much potential energy is contained in the compressed spring?
a) 49 J
b) 2.45 J
c) 122 J
d) 0.061 J
e) I cannot tell from the information given.
Answer:
Option D. 0.061 J
Explanation:
We'll begin by converting 5 cm to m. This can be obtained as follow:
100 cm = 1 m
Therefore,
5 cm = 5 cm × 1 m / 100 cm
5 cm = 0.05 m
Next, we shall convert 250 g to Kg. This can be obtained as follow:
1000 g = 1 Kg
Therefore,
250 g = 250 × 1 Kg / 1000
250 g = 0.25 Kg
Next, we shall determine the weight of the object. This can be obtained as follow:
Mass (m) = 0.25 Kg
Acceleration due to gravity (g) = 9.8 m/s²
Weight (W) =?
W = m × g
W = 0.25 × 9.8
W = 2.45 N
Next, we shall determine the spring constant. This can be obtained as follow:
Compression (e) = 0.05 m
Weight = Force (F) = 2.45 N
Spring constant (K) =?
F = Ke
2.45 = K × 0.05
Divide both side by 0.05
K = 2.45 / 0.05
K = 49 N/m
Finally, we shall determine the potential energy contained in the compressed spring. This can be obtained as follow:
Compression (e) = 0.05 m
Spring constant (K) = 49 N/m
Energy (E) =?
E = ½Ke²
E = ½ × 49 × (0.05)²
E = 24.5 × 0.0025
E = 0.061 J
Therefore, the potential energy contained in the compressed spring is 0.061 J
What type of specialized cell in the eye is used for detecting low levels of light?
Answer:
There are about six to seven million cones in a human eye and are most concentrated towards the macula. Cones are less sensitive to light than the rod cells in the retina (which support vision at low light levels), but allow the perception of color.
Answer:
Rods
Explanation:
There are about six to seven million cones in a human eye and are most concentrated towards the macula. Cones are less sensitive to light than the rod cells in the retina (which support vision at low light levels), but allow the perception of color.
An object's velocity/speed increases, multiplied by a factor of 7. What factor would its Kinetic Energy increase by?
Answer:
k.E= 49 ms^-2
Explanation:
k.E= 1/2 mv^2
From that formula of k.E
K.E is directly proportional to the ( velocity)^2
K.E directly proportional to (7)^2
so that k.E increase by 49
In a symbiotic relationship,
a. one organism benefits while its host gets nothing in return.
b. bacteria takes food from your stomach, but does nothing for you.
c. both organisms involved benefit or are neutrally affected.
d. your body produces vitamins and then uses them for nutrition
In a symbiotic relationship, both organisms involved benefit or are neutrally affected. Symbiosis is a close and long-term interaction between two different species.
The term "symbiosis" encompasses mutualism, commensalism, and parasitism. In mutualism, both organisms benefit from the interaction, such as in the case of bees and flowers where bees obtain nectar and pollen while also helping flowers to pollinate.
In commensalism, one organism benefits while the other is neither helped nor harmed, such as remora fish that attach to sharks for transportation and feeding on scraps left by the shark. In parasitism, one organism benefits while the other is harmed, such as ticks that feed on blood from a host animal.
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