Audrey, an astronomer is searching for extra-solar planets using the technique of relativistic lensing. Though there are believed to be a very large number of planets that can be found this way, actually finding one takes time and luck; and finding one planet does not help at all with finding planets of other stars in the same part of the sky. Audrey is good at it, and finds one planet at a time, on average once every three months. a.) Find the expected value and
Answer:
- the expected value is 8
- the standard deviation is 2.8284
Explanation:
Given the data in the question;
The model N(t), the number of planets found up to time t, as a poisson process,
∴ N(t) has distribution of poisson distribution with parameter (λt)
so
the mean is;
λ = 1 every month = 1/3 per month
E[N(t)] = λt
E[N(t)] = (1/3)(24)
E[N(t)] = 8
Therefore, the expected value is 8
For poisson process, Variance and mean are the same,
Var[N(t)] = Var[N(24)]
Var[N(t)] = E[N(24)]
Var[N(t)] = 8
so the standard deviation will be;
σ[N(24)] = √(Var[N(t)] )
σ[N(24)] = √(8 )
σ[N(24)] = 2.8284
Therefore, the standard deviation is 2.8284
A 85-W lamp is connected to 100 V. What is the resistance of the lamp?
An object, with mass 64 kg and speed 14 m/s relative to an observer, explodes into two pieces, one 2 times as massive as the other; the explosion takes place in deep space. The less massive piece stops relative to the observer. How much kinetic energy is added to the system during the explosion, as measured in the observer's reference frame
Answer:
K_f = 1881.6 J
Explanation:
To solve this exercise, let's start by finding the velocities of the bodies.
We define a system formed by the initial object and its parts, with this the forces during the explosion are internal and the moment is conserved
initial instant. Before the explosion
p₀ = M v₀
final instant. After the explosion
p_f = m₁ v + m₂ 0
the moeoto is preserved
p₀ = p_f
M v₀ = m₁ v
v = [tex]\frac{m_1}{M}[/tex] v₀
in the exercise they indicate that the most massive part has twice the other part
M = m₁ + m₂
M = 2m₂ + m₂ = 3 m₂
m₂ = M / 3
so the most massive part is worth
m₁ = 2 M / 3
we substitute
v = ⅔ v₀
with the speed of each element we can look for the kinetic energy
initial
K₀ = ½ M v₀²
Final
K_f = ½ m₁ v² + 0
K_f = ½ (⅔ M) (⅔ v₀)²
K_f = [tex]\frac{8}{27}[/tex] (½ M v₀²)
K_f = [tex]\frac{8}{27}[/tex] K₀
the energy added to the system is
ΔK = Kf -K₀
ΔK = (8/27 - 1) K₀
ΔK = -0.7 K₀
K_f = K₀ + ΔK
K_f = K₀ (1 -0.7)
K_f = 0.3 K₀
let's calculate
K_f = 0.3 (½ 64 14²)
K_f = 1881.6 J
Two ice skaters, with masses of 50 kg and 75 kg , are at the center of a 30 m -diameter circular rink. The skaters push off against each other and glide to opposite edges of the rink. Part A If the heavier skater reaches the edge in 30 s , how long does the lighter skater take to reach the edge
Answer:
t = 20 s
Explanation:
Assuming no other forces acting on the skaters when they push off against each other, and that we can neglect friction, total momentum must be conserved.The initial momentum is just zero, because both skaters are at rest.So, when both are gliding to opposite edges of the rink, at any moment, we can write the following expression:[tex]p_{f} = m_{1} * v_{1} = m_{2} * v_{2} (1)[/tex]
where m₁ = 50 kg, m₂ = 75 kg.We know that the heavier skater reaches the edge in 30 s.Since the distance from the center to any point on the edge is just half the diameter, we can find the speed of the heavier skater as follows:[tex]v_{2} = \frac{15m}{30s} = 0.5 m/s (2)[/tex]
Replacing m₁, m₂ and v₂ in (1), we can solve for the only unknown (v₁) as follows:[tex]v_{1} = \frac{m_{2}*v_{2}}{m_{1} } = \frac{75 kg*0.5m/s}{50kg} = 0.75 m/s (3)[/tex]
Since the distance to the opposite edge from the center is the same than for the heavier skater, we can find the time needed for the lighter one to reach the edge as follows:[tex]t_{1} = \frac{15m}{0.75m/s} = 20 s (4)[/tex]I need help with this review question. I’ll give extra points.
Answer:
1.9m/s²
Explanation:
Use the equation v=u+at, where v is the final speed, u is the initial speed, a is the acceleration and t is the time.
v=u+at
15.3=0+a(8)
a=15.3/8
a= 1.9125 m/s²
Are all harmful effects of smoking reversible? Explain your answer.
A woman shouts at a boy who is underwater what happens to the speed of the sound wave as it moves from the air into the water
Answer:
B. it increases
Explanation:
As shown in the table provided, the speed of sound in water (1493 m/s) is greater than the speed of sound in air (346 m/s).
Answer:
B is the correct answer.
Explanation:
In a double-slit experiment, the slits are illuminated by a monochromatic, coherent light source having a wavelength of 527 nm. An interference pattern is observed on the screen. The distance between the screen and the double-slit is 1.54 m and the distance between the two slits is 0.102 mm. A light wave propogates from each slit to the screen. What is the path length difference between the distance traveled by the waves for the fifth-order maximum (bright fringe) on the screen
Answer:
Λ = 5.14 10⁻⁴ m
Explanation:
This is a double slit experiment, which for the case of constructive interference
d sin θ = m λ
let's use trigonometry
tan θ = y / L
as the angles are very small
tan θ = [tex]\frac{sin \theta}{cos \theta}[/tex] = sin θ
sin θ = y / L
we substitute
d y / L = m λ
y = m λ L / d
we calculate for the interference of order m = 5
y = 5 527 10⁻⁹ 1.54/0.102 10⁻³
y = 3.978 10⁻² m
Now we can find the difference in length between the two rays, that of the central maximum and this
let's use the Pythagorean theorem
L’= [tex]\sqrt{L^2 +y^2}[/tex]
L ’= [tex]\sqrt{1.54^2 +(3.978 \ 10^{-2})^2 }[/tex]
L ’= 1.54051 m
optical path difference
Λ = L’- L
Λ = 1.54051 - 1.54
Λ = 5.14 10⁻⁴ m
Hi please zoom in to see it clearly, uh you don’t have to answer them all but it would be nice !!! (no links please) :)
Explanation:
Newton's second law of motion states that the external force is directly proportional to the rate of change of momentum. Mathematically, Newton's second law of motion is given by :
F = ma
Where
m is the mass and a is the acceleration
If there is a smaller mass, it would need a weaker force to accelerate it as the force is directly proportional to the mass. Hence, the correct option is (d).
Daryl ties a rope to a brick and lifts the brick straight up. The free-body
diagram below shows the brick when it is suspended above the ground.
Force 1
Force 2
What is force 1 in this diagram?
O A. Friction
OB. Tension
O C. Normal force
O D. Weight
The force 1 is tension force.
To find the correct statement among all the options, we need to know more about friction, tension, normal force and weight.
What is friction?Friction force is found between two surfaces when one is kept or moved on another surface.It is directed opposite to the direction of motion.What is tension force?When any object is hanged by an thread or rope, that object exerts a force on that rope. This force is called as tensional force.It's directed from along the rope towards the point of hanging.What is normal force?When an object is kept on a surface, the surface exerts a force on the object to oppose the weight of the object which is the normal force.It's perpendicular to the surface that an object contacts.What is weight?Weight is the gravitational force exerted by earth on that object. It's always directed towards the center of the earth.Thus, we can conclude that the correct option is (B).
Learn more about tension here:
https://brainly.com/question/2008782
#SPJ2
a 4.5 Hz wave has a wavelength of 0.8m. what is the speed
0.18 m/s
5.6m/s
5.3m/s
3.6m/s
Answer:
Explanation
the atom of an element x has 21protrons and 23neutrons. What is the
(a) Electron number
(b) Mass number
(c) Neutron number
A bird travels at a speed of 14.2 m/s for 514 meters. How many seconds did it
fly?
Answer:
0.54 sec
Explanation:
Answer:
Time = 36.19 secondsExplanation:
Speed = 14.2 m/s
Distance = 514 m
Time = Distance / Speed
Time = 514 / 14.2
Time = 36.19 seconds
PLEASE HELP
the graph shows a plot of an objects velocity versus time for 15 seconds. is the acceleration of the object constant or changing? how do you know? what does this tell you about the net force on the object?
Answer:
It cannot be constant because if it does not change and each time it increases its strength and speed.
Explanation:
Which layer of the atmosphere is the least dense?
Question 5 options:
exosphere
thermosphere
mesosphere
troposphere
the exosphere is the least dense
Answer:
exosphere
Explanation: Just took the quiz and got an A, 100%
If an athlete runs the triathlon of 10 km in 2 hours, what is her average speed in kilometers per hour?
Answer: 5 km per hour
Explanation:
if in 10 km there is 2 hours, then 10 divided by 2 is 5.
What is Newton's scientific view?
Answer:
Newton's first law of motion concerns any object that has no force applied to it.
Explanation:
three laws of motion and the law of universal gravitation.
4) Which statement about teamwork is not true?
A) Team members should not have to make personal sacrifices for the success of the team.
B) To be successful, all team members need to agree about how to achieve the goal.
C) To achieve agreement, teams must be able to communicate and negotiate.
D) Team members need to be ready to resolve conflicts in an open and honest way
Answer: A) Team should not have to make personal sacrifices for the success of the team.
Explanation:
You are watching a s Saturday morning cartoon concerning a jungle hero called George of the Jungle. George attempts to save a friend, an ape named Ape, from a stampeding herd of wildebeests. Ape is at the base of a tall tree which has a vine attached to its top. George is in another tree holding the other end of the vine. George plans to swing down from the tree, grab Ape at the bottom of the swing, and continue up to safety on a ledge which is half of George's initial height in the tree. Assuming that Ape weights the same as George, will they successfully make it to the top of the ledge? If you believe they do, how high a ledge could they make it to? If you disagree, suggest what could be done for George to save Ape.
Answer:
I don't think so because if Ape was the same weight as george I don't
think he can hold him but maybe so let's say he could hold his own ape then Yes I think he could make it to the ledge Now I think they could make it to the ledge which was half the size.
Sorry if this sounded weird English is my 2nd language Oh and if this helped please give brainiest thank you <3
Heeelp me faaast plllsss
Answer:
the first one
Explanation:
cartridge fuse
no links or i will report. What is the potential energy of stretched spring, if the spring constant is 40 N/m and the elongation is 5 cm?
Answer: 0.05 J
Explanation:
List all variables before solving:
K = 40 N/m
x = 5 cm (convert to 0.05 m)
Use the equation for potential energy (PE):
PE = [tex]\frac{1}{2}[/tex] k[tex]x^{2}[/tex]
Plug in the given variables and solve:
PE = ( [tex]\frac{1}{2}[/tex] ) (40 N/m) (0.05 m)^2
The answer is 0.05 J
Which of the following happens to
density as air pressure decreases?
С C
A. Density increases.
B. Density stays the same.
C. Density decreases.
D. There is no correlation between air pressure and
density.
Explanation:
As pressure increases, with temperature constant, density increases. Conversely when temperature increases, with pressure constant, density decreases. Air density will decrease by about 1% for a decrease of 10 hPa in pressure or 3 °C increase in temperature.
The augue
1) What will be number of image if the angle
between two mirroro is
a) 45
b:36
One end of a meter stick is pinned to a table, so the stick can rotate freely in a plane parallel to the tabletop. Two forces, both parallel to the tabletop, are applied to the stick in such a way that the net torque is zero. The first force has a magnitude of 2.00 N and is applied perpendicular to the length of the stick at the free end. The second force has a magnitude of 6.00 N and acts at a 42.9o angle with respect to the length of the stick. Where along the stick is the 6.00-N force applied? Express this distance with respect to the end of the stick that is pinned.
Answer:
x = 0.455 L
Explanation:
For this exercise we must use the rotational equilibrium condition
Σ τ = 0
it has two forces, the first is perpendicular to the rod, so its stub is
τ₁ = F₁ L
the second force is applied with an angle, so we can use trigonometry to find its components
sin θ = F_parallel / F₂
cos θ = F_perpendicular / F₂
F_parallel = F₂ sin θ
F _perpendicular = F₂ cos θ
torque is
τ₂ = F_perpendicular x + F_parallel 0
the parallel force is on the rod therefore its distance is zero
we apply the equilibrium equation
τ₁ - τ₂ = 0
F₁ L = F₂ cos θ x
x = [tex]\frac{L}{cos \theta} \ \frac{F_1}{F_2}[/tex]
let's calculate
x = [tex]\frac{L}{cos \ 42.9} \ \frac{2.00}{6.00}[/tex]
x = 0.455 L
If you double the diameter of a telescope, you double its light-collecting area.
True
False
Answer:true
Explanation:because the double lights
I need help with this
1. Who invented Table Tennis?
Answer:
So the answer to the question "who invented table tennis?" is ... Englishman David Foster. An English Patent (number 11,037) was filed on 15 July 1890 when David Foster of England introduced the first action game of tennis on a table in 1890. Only one example is known to have survived and it's now on display in the ITTF Museum.
Explanation:
A bird is flying directly toward a stationary bird-watcher and emits a frequency of 1490 Hz. The bird-watcher, however, hears a frequency of 1505 Hz. What is the speed of the bird, expressed as a percentage of the speed of sound
Answer:
The speed of the bird is 1.00% of the speed of sound.
Explanation:
The speed of the bird can be found by using the Doppler equation:
[tex] f = f_{0}(\frac{v - v_{r}}{v - v_{s}}) [/tex]
Where:
v: is the speed of sound = 343 m/s
f₀: is the frequency emitted = 1490 Hz
f: is the frequency observed = 1505 Hz
[tex]v_{r}[/tex]: is the speed of the receiver = 0 (it is stationary)
[tex]v_{s}[/tex]: is the speed of the source =?
The minus sign of [tex]v_{s}[/tex] is because the source is moving towards the receiver.
By solving the above equation for [tex]v_{s}[/tex] we have:
[tex] v_{s} = v - \frac{f_{0}*v}{f} = 343 - \frac{1490*343}{1505} = 3.42 m/s [/tex]
The above speed in terms of the speed of sound is:
[tex]\% v_{s} = \frac{3.42}{343}\times 100 = 1.00 \%[/tex]
Therefore, the speed of the bird is 1.00% of the speed of sound.
I hope it helps you!
Please help me with this question. Every help is appreciated.
Answer:
Change in KE = +1.96×10^4 J while the change in ME = 0 J
A baby carriage is sitting at the top of a hill that is 21 m high. The carriage with the baby weighs 20
kg. The carriage has
energy. Calculate it
Answer:
Energy in carriage (Potential energy) = 4,116 J
Explanation:
Given:
Mass of baby = 20 kg
Height = 21 m
Find:
Energy in carriage (Potential energy)
Computation:
The energy accumulated in an object as a result of its location relative to a neutral level is known as potential energy.
In carriage accumulated energy is potential energy.
Energy in carriage (Potential energy) = mgh
Energy in carriage (Potential energy) = (20)(9.8)(21)
Energy in carriage (Potential energy) = 4,116 J