c. a natural process
It is a natural process
Each of the four expansion models (recollapsing, critical, coasting, and accelerating) predict different ages for the universe, given the current expansion rate. Why is this
Answer:
This is because the age of the universe is determined by the pace of expansion in the past, and each model forecasts a different pace.
Explanation:
The age of the universe is determined by the pace of expansion in the past, and each model forecasts a different pace.
This is due to the fact that the expansion rate in the coasting model is constant and never changes. Because the cosmos is growing faster now than during the old days, recollapsing and critical models give shorter ages. According to the accelerating model, the universe is growing at a slower rate currently than in the past, implying an older age.
A closely wound, circular coil with radius 2.80 cm has 790 turns. Part A What must the current in the coil be if the magnetic field at the center of the coil is 0.0760 T
Answer:
[tex]I=11.1A[/tex]
Explanation:
From the question we are told that:
Radius [tex]R=2.80[/tex]
Turns [tex]N=790[/tex]
Magnetic field B=0.0760
Generally the equation for Magnetic field at the center of the coil is mathematically given by
[tex]B=\frac{\mu NI}{2r}[/tex]
[tex]0.076=\frac{4\p*10^-^7*790*I}{2*0.028}[/tex]
[tex]I=\frac{0.076*2*0.028}{4\p*10^{-7}*790}[/tex]
[tex]I=11.1A[/tex]
The position of a particle at time tt is s(t)=t3+3t.s(t)=t3+3t. Compute the average velocity over the time interval [2,5][2,5] and estimate the instantaneous velocity at t=2.t=2. (Give your answers as whole numbers.)
(a) 42m/s
(b) 15m/s
Explanation:
Given:
The position of a particle at time t
s(t) = t³ + 3t
(i) To compute the average velocity
Average velocity ([tex]V_{avg}[/tex]) is given by the quotient of the change in position and change in time at a given interval of time. i.e
[tex]V_{avg}[/tex] = Δs / Δt
[tex]V_{avg}[/tex] = (s₂ - s₁) / (t₂ - t₁) --------------------(ii)
Given interval of time is [2,5]
Therefore,
t₁ = 2
t₂ = 5
s₁ = position of the particle at t₁.
This is found by substituting t = 2 into equation (i)
s₁ = (2)³ + 3(2)
s₁ = 8 + 6 = 14
s₂ = position of the particle at t₂
This is found by substituting t = 5 into equation (i)
s₂ = (5)³ + 3(5)
s₂ = 125 + 15 = 140
Now, substitute t₁, t₂, s₁ and s₂ into equation (ii) as follows;
[tex]V_{avg}[/tex] = (s₂ - s₁) / (t₂ - t₁)
[tex]V_{avg}[/tex] = (140 - 14) / (5 - 2)
[tex]V_{avg}[/tex] = 126 / 3
[tex]V_{avg}[/tex] = 42
Therefore, the average velocity is 42m/s
(ii) To compute the instantaneous velocity.
The instantaneous velocity is the velocity of the particle at a given instant in time.
The given instant in time is t = 2.
To get the instantaneous velocity (V), differentiate equation (i) with respect to t as follows;
V = [tex]\frac{ds}{dt}[/tex]
V = [tex]\frac{d(t^3 + 3t)}{dt}[/tex]
V = 3t² + 3
Now substitute the value of t = 2 into the above equation
V = 3(2)² + 3
V = 12 + 3
V = 15
Therefore, the instantaneous velocity at t = 2 is 15m/s
while hunting in a cave a bat emits sounds wave of frequency 39 kilo hartz were moving towards a wall with a constant velocity of 8,32 meters per second take the speed of sound as 340 meters per second calculate frequency
Complete question:
while hunting in a cave a bat emits sounds wave of frequency 39 kilo hartz were moving towards a wall with a constant velocity of 8.32 meters per second take the speed of sound as 340 meters per second. calculate the frequency reflected off the wall to the bat?
Answer:
The frequency reflected by the stationary wall to the bat is 41 kHz
Explanation:
Given;
frequency emitted by the bat, f = 39 kHz
velocity of the bat, [tex]v_b[/tex] = 8.32 m/s
speed of sound in air, v = 340 m/s
Apply the doppler-effect principle to solve this problem.
The apparent frequency of sound striking the wall is calculated as;
[tex]f' = f(\frac{v}{v- v_b} )\\\\f' = 39,000(\frac{340}{340 -8.32} )\\\\f' = 39978.29 \ Hz[/tex]
The frequency reflected by the stationary wall to the bat is calculated as;
[tex]f_s = f'(\frac{v + v_b}{v} )\\\\f_s = 39978.29(\frac{340 + 8.32}{340} )\\\\f_s = 40,956.56 \ Hz[/tex]
[tex]f_s\approx 41 \ kHz[/tex]
Name the state of matter in which
(a) Rate of diffusion is fastest (b) diffusion does not take place.
plss essay
Answer:
A
Explanation:
You throw a glob of putty straight up toward the ceiling, which is 3.50 mm above the point where the putty leaves your hand. The initial speed of the putty as it leaves your hand is 9.50 m/sm/s. Part A What is the speed of the putty just before it strikes the ceiling
Answer: [tex]4.65\ m/s[/tex]
Explanation:
Given
Distance putty has to travel is 3.5 m
The initial speed of putty is 9.50 m/s
Using equation of motion to determine the velocity of putty just before it hits ceiling
[tex]v^2-u^2=2as[/tex]
[tex]\Rightarrow v^2-(9.5)^2=2(-9.8)(3.5)\\\\\Rightarrow v^2=9.5^2-68.6\\\Rightarrow v=\sqrt{90.25-68.6}\\\Rightarrow v=4.65\ m/s[/tex]
So, the velocity of putty just before hitting is [tex]4.65\ m/s[/tex]
True or false, wrrect the false
statement:
• The magnetic field created by a flat coil is
uniform.
• Inside a solenoid, the lines of field are
oriented from the north face to the south
face.
• The magnetic field outside Helmholtz
coils is uniform.
• Le champ B à l'intérieur d'un solénoïde
est uniforme.
• The magnitude of B, created by a flat coil
of radius R, at any point in its plane is
B= 2m x 10-NI
R
• The designation of the faces of a wil
depend the sense of the current
traversing it.
Answer:
false
Explanation:
100 POINTS AND BRAINLIEST!!! How does the egg sucked into a glass bottle trick work?
Answer: The egg will get sucked into the bottle. To get the egg out of the bottle, turn the bottle upside down and blow into it, so that the egg acts as a one-way valve. The increased air pressure in the bottle will cause the egg to pop back out.
Explanation:
Quickly place the egg over the mouth of the bottle. The egg will get sucked into the bottle. To get the egg out of the bottle, turn the bottle upside down and blow into it, so that the egg acts as a one-way valve. The increased air pressure in the bottle will cause the egg to pop back out.
A disk-shaped platform has a known rotational inertia ID. The platform is mounted on a fixed axle and rotates in a horizontal plane with an initial angular velocity of ÏD in the counterclockwise direction as shown. After an unknown time interval, the disk comes to rest. A single point on the disk revolves around the center axle hundreds of times before the disk comes to rest. Frictional forces are considered to be constant.
In a different experiment, the original disk is replaced with a disk for which frictional forces are considered to be negligible. The disk is set into motion such that it rotates with a constant angular speed. As the disk spins, a small sphere of clay is dropped onto the disk, and the sphere sticks to the disk.
Required:
Write down the claims which are correct about the angular momentum and the total kinetic energy of the disk-sphere system immediately before and immediately after the collision.
Answer:
Explanation:
The angular momentum of that same disk-sphere remains unchanged the very same way before and after the impact of the collision when the clay sphere adheres to the disk.
[tex]\mathbf{I_w}[/tex] = constant.
The overall value of such moment of inertia is now altered when the clay spherical sticks. Due to the inclusion of the clay sphere, the moment of inertia will essentially rise. As a result of this increase, the angular speed w decreases in value.
Recall that:
The Kinetic energy is given by:
[tex]\mathbf{K = \dfrac{1}{2} Iw^2} \\ \\\mathbf{K = \dfrac{1}{2} lw*w}[/tex]
where;
[tex]\mathbf{I_w}[/tex] is constant and w reduces;
As a result, just after the collision, the system's total kinetic energy decreases.
The total kinetic energy of the system decreases after the collision.
What is angular momentum?The angular momentum of any rotating body is defined as the product of the moment of inertia of the body and the angular velocity of the body.
Now from the question, we can see that the angular momentum of the body remains constant before and after the impact of the collision when the clay sphere adheres to the disk.
So angular momentum will be
[tex]Iw[/tex] = constant.
The overall value of such a moment of inertia is now changed when the clay spherical sticks. Due to the inclusion of the clay sphere, the moment of inertia will essentially rise. As a result of this increase, the angular speed w decreases in value.
The Kinetic energy is given by:
[tex]KE=\dfrac{1}{2} Iw^2[/tex]
[tex]KE= \dfrac{1}{2} Iw\times w[/tex]
Since the angular momentum [tex]Iw[/tex] is constant and w is reducing then ultimately the energy of the system is decreasing.
Thus the total kinetic energy of the system decreases after the collision.
To know more about Angular momentum follow
https://brainly.com/question/25677703
Some students are making a domino cascade for a fair project and want to use a ball rollingup and then down an incline in one part of it. The timing has to be very precise so theyneed to know exactly how long it will take the ball to go up and down. They have measuredthe acceleration of the ball on the incline to be 2.5 m/s2. If the ball starts part way up theramp, rolls up for 1.1 m, then down 0.7 m past its starting point, how long will it take
Answer:
total time taken is 2.1389 seconds
Explanation:
Given the data in the question and as illustrated in the diagram below;
They have measured the acceleration of the ball on the incline to be 2.5 m/s²
a = -2.5 m/s² { negative because its acting downward }
from the diagram, Motion from B to C will be;
v² = u² + 2as
given that distance s = 1.1 m
we substitute
v² - u² = 2as
(0)² - u² = 2 × (-2.5 m/s ) × 1.1 m
-u² = -5.5
u = √5.5
so Initial speed; u = 2.345 m/s
to get the time, we use the equation of motion;
v = u + at
we substitute
0 = 2.345 m/s + ( -2.5 m/s² × t₁ )
2.5t₁ = 2.345
t₁ = 2.345 / 2.5
t₁ = 0.938 s
Now, from C to B
we determine t₂
s = vt₂ + [tex]\frac{1}{2}[/tex]at₂²
1.1 m = 0×t₂ + [tex]\frac{1}{2}[/tex] × 2.5 m/s² × t₂²
1.1 m = [tex]\frac{1}{2}[/tex] × 2.5 m/s² × t₂²
1.1 m = 1.25 m/s² × t₂²
t₂² = 1.1 m / 1.25 m/s²
t₂² = 0.88 s²
t₂ = √0.88 s²
t₂ = 0.938 s
Next, from B to A; t₃ will be;
s = ut₃ + [tex]\frac{1}{2}[/tex]at₃²
we substitute
0.7 m = (2.345 m/s)t₃ + [tex]\frac{1}{2}[/tex] × 2.5 m/s × t₃²
0.7 m = (2.345 m/s)t₃ + ( 1.25 m/s )t₃²
1.25t₃² + 2.345t₃ - 0.7 = 0
using; x = [ -b ± √( b² - 4ac ) ] / 2a
we substitute
x = = [ -2.345 ± √( (2.345)² - (4 × 1.25 × -0.7) ) ] / 2(1.25)
x = [ -2.345 ± √( 5.499 + 3.5 ) ] / 2.5
x = [ -2.345 ± √( 8.999 ) ] / 2.5
x = [ -2.345 ± 2.9998 ] / 2.5
x = ( [ -2.345 - 2.9998 ] / 2.5 ) or ( [ -2.345 + 2.9998 ] / 2.5 )
x = -2.1379 or 0.2629
hence t₃ = 0.2629 s
∴ Total time = t₁ + t₂ + t₃
Total time = 0.938 s + 0.938 s + 0.2629 s
Total time = 2.1389 seconds
Therefore, total time taken is 2.1389 seconds
g If we decreased the wavelength by a factor of 2 and also increased the distance D by a factor of 2, the fringes on the screen would be...
Answer:
y = y₀ / 4
Explanation:
In a double slit experiment the constructive interference lines are given by
d sin θ = m λ
if we use trigonometry
tan θ = y / L
as in these experiments the angles are very small
tan θ = sin θ /cos θ = sin θ
we substitute
sin θ = y / L
d y / L = m λ
let's use a subscript "o" for the initial values
I = m λ₀ L /d₀
They ask us to decrease the wavelength by 2
λ = λ₀ / 2
the distance in the slit is increased by a factor of two
d = 2 d₀
we substitute
2d₀ y/L = m λ₀/2
y = m λ₀ L/d₀ ¼
y = y₀ / 4
PLS ANSWER FAST WILL GIVE BRAINLY!!!!!!!
explain at least one way that engineers and scientists work to prevent coastal erosion.
Answer:
the answer is the explaination
Explanation:
Present beach erosion prevention methods include sand dunes, vegetation, seawalls, sandbags, and sand fences. Based on the research conducted, it is evident that new ways to prevent erosion must be obtained. Each way that is currently used has extensive negative effects on beaches and their natural tendencies.
Answer:
They will construct strong sea walls with the intent to protect the coastline and infrastructure that could be affected by erosion.
Explanation:
A standing wave with 5 loops is created on a string that is 0.75 m long. If the
wave has a velocity of 300 m/s, what is the frequency of the wave?
1000 Hz
400 Hz
225 Hz
90 Hz
None of the above
wave velocity = frequency × wavelength
300 = frequency × 0.75
Frequency = 300÷0.75 = 400 HZ
Calculate the spring constant of the spring in a child's pogo stick if the child has a mass of 32 kg and bounces once every 2.7 seconds
Answer:
The spring constant is 173.12 N/m.
Explanation:
mass, m = 32 kg
Period, T = 2.7 s
let the spring constant is K.
Use the formula of period,
[tex]T = 2\pi\times \sqrt \frac{m}{K}\\\\2.7 =2\times 3.14\sqrt\frac{32}{K}\\\\K = 173.12 N/m[/tex]
1.A motor is rated at 1.5 hp. At what speed in m/s can this motor raise a
200 kg load?
2. A bucket of water with a total weight of 50 Newtons is lifted at constant
velocity up a 10 meter deep well. If it takes 20 seconds to raise the bucket
this distance, what is the power required to lift the bucket?
Answer:
1. 0.57 m/s
2. 25 Watts
Explanation:
1. Determination of the speed.
We'll begin by converting 1.5 hp to watt (W). This can be obtained as follow:
1 hp = 745.7 W
Therefore,
1.5 hp = 1.5 hp × 745.7 W / 1 hp
1.5 hp = 1118.55 W
Next, we shall determine the force. This can be obtained as follow:
Mass (m) = 200 Kg
Acceleration due to gravity (g) = 9.8 m/s²
Force (F) =?
F = m × g
F = 200 × 9.8
F = 1960 N
Finally, we shall determine the speed. This can be obtained as follow:
Power (P) = 1118.55 W
Force (F) = 1960 N
Speed (v) =?
P = F × v
1118.55 = 1960 × v
Divide both side by 1960
v = 1118.55 / 1960
v = 0.57 m/s
Thus, the speed is 0.57 m/s
2. Determination of the power.
We'll begin by calculating the velocity. This can be obtained as follow:
Displacement = 10 m up
Time = 20 s
Velocity =?
Velocity = Displacement / time
Velocity = 10 / 20
Velocity = 0.5 m/s
Finally, we shall determine the power. This can be obtained as follow:
Velocity (v) = 0.5 m/s
Force (F) = 50 N
Power (P) =?
P = F × v
P = 50 × 0.5
P = 25 Watts
Therefore, the power required to lift the bucket is 25 Watts
DUE IN 1 MINUTE PLS ANSWER QUICK ...A sound wave moving with a speed of 1500 m/s is sent from a submarine to the ocean floor. It reflects off the
ocean floor and is received 15s later. What is the distance between the submarine and the ocean floor?
Answer:
s = 11250 m = 11.25 km
Explanation:
The distance covered by the sound wave while traveling from submarine to ocean floor and then back to submarine can be given as follows:
[tex]s = vt[/tex]
but, the distance between the floor and the submarine will be half of this value:
[tex]s = \frac{1}{2}vt[/tex]
where,
s = distance between submarine and ocean floor = ?
v = velocity of sound = 1500 m/s
t = time taken for the round trip = 15 s
Therefore,
[tex]s = \frac{1}{2}(1500\ m/s)(15\ s)[/tex]
s = 11250 m = 11.25 km
I need help with this assignment
what is potential energy??
Answer:
the energy possessed by a body by virtue of its position relative to others, stresses within itself, electric charge, and other factors.
hope this helps
have a good day :)
Explanation:
Answer:
Potential Energy is the stored energy in an object or system because of its position or configuration.
Explanation:
Example: Water at the top of a waterfall, before the precipice.
Two physics students are arguing about superconductors and their discovery, Jeffe says that he can use a
thermometer and a plug that generates electric current to mimic the experiment and make a superconductor since the
thermometer contains mercury. Sigorne says that he is wrong. Who should win the argument?
O Sigorne, because Jeffe can't use mercury to create a superconductor
O Sigorne, because Jeffe would have to cool the mercury as well
O Jeffe, because he has all of the materials to make a superconductor
O Jeffe, because superconductors are simple to make as long as there is a metal and a current
Answer:
B on edge2020-2021
Explanation:
what's the difference between mass and inertia in a tabular form
Answer:
to be honest i dont know
Explanation:
^^
Parallel rays from a distant object are traveling in air and then are incident on the concave end of a glass rod with a radius of curvature of 15.0 cm. The refractive index of the glass is 1.50. What is the distance between the vertex of the glass surface and the image formed by the refraction at the concave surface of the rod? Is the image in the air or in the glass?
Answer:
the distance of image from the vertex is 45 cm and the image formed is in the glass.
Explanation:
distance of object, u = - infinity
radius of curvature, R = - 15 cm
refractive index, n = 1.5
Let the distance of image is v.
Use the formula
[tex]-\frac{n1}{u}+\frac{n2}{v}=\frac{n2- n1}{R}\\\\-\frac{1}{\infty }+\frac{1.5}{v}=\frac{1.5-1}{-15}\\\\v=45 cm[/tex]
The image is in the glass.
state the two motion equations.
Answer:
Equations of motion relate the displacement of an object with its velocity, acceleration and time. s=vt where s is the displacement, v the (constant) speed and t the time over which the motion occurred. ...
Displacement with negative acceleration: s, equals, v, t, minus, one half, a, t, square...
Displacement with positive acceleration: s, equals, u, t, plus, one half, a, t, squared,s...
Velocity squared: v, squared, equals, u, squared, plus, 2, a, s,v2=u2+2as
Velocity: v, equals, u, plus, a, t,v=u+at
A force of 350 newtons stretches a spring 30 centimeters. How much work is done in stretching the spring from 20 centimeters to 50 centimeters
Answer:
52.5 J
Explanation:
Applying,
Hook's law,
F = ke............... Equation 1
Where F = Force, k = spring constant, e = extension.
make k the subject of the equation
k = F/e............ Equation 2
From the question,
Given: F = 350 Newtons, e = 30 cm = 0.3 m
Substitute these values into equation 2
k = 350/0.3 N/m
Also,
W = 1/2(ke²).................. Equation 3
Where W = work done in stretching the spring.
Also given: e = (50-20) cm = 30 cm = 0.3 m, k = 350/0.3 N/m
Substitute these values into equation 3
W = 1/2(350/0.3)(0.3²)
W = 350×0.3/2
W = 52.5 J
Explain in terms of impulse how padding reduces forces in a collision. State this in terms of a real example, such as the advantages of a carpeted vs. tile floor for a day care cente
Answer:
Impulse = Average force x time of contact
Explanation:
Impulsive force is a force which is very large but applied on a body for a very small duration of time.
Impulse is given by the change in momentum of the body.
Impulse = Average force x small time interval
When padding is there, the time interval of contact is large and thus, the force exerted by the body is small.
So, when a person falls on the tile floor, there is no compression and thus, the time of contact is very small and thus the impulsive force is very large, due to which the body may damage.
So, when a person falls on the carpeted floor, there is a compression and thus, the time of contact is comparatively large and thus the impulsive force is small, due to which the body may safe.
Identical net forces act for the same length of time on two different spherical masses. Which of the following describes the change in linear momentum of the smaller mass compared to that of the larger mass?
a. it is smaller than the change in linear momentum of the larger mass but not zero.
b. It is larger than the change in linear momentum of the larger mass.
c. It is equal to the change in linear momentum of the larger mass.
d. It is zero
Answer:
the correct answer is c
Explanation:
In this exercise we seek the momentum
I = F t
this value is set because forces and time are given.
Now we can use the relationship between linear momentum and momentum
I = p_f - p₀
I = m v_f - m v₀
suppose that the two spheres depart with the same initial velocity
Let's analyze these results, the value of the impulse is the same, so the body of lower mass must acquire greater speed or momentum
consequently the lighter sphere acquires more final speed, but the change of momentum is the same in the two spheres
Consequently the correct answer is c
PLS ANSWER WORTH 10 POINTS PLS HELP
Answer:
the answer should be D
Explanation:
Because if you want to earn your goals you must complete small goals to earn big goals
Determine the amount of work done on an ideal gas as it is heated in an enclosed thermally insulated cylinder topped with a freely moving piston. The cylinder contains of n moles of the gas and the temperature is raised from T1 to T2. The piston has a mass m and a cross sectional area A.
Answer:
W = 3/2 n (T₁- T₂)
Explanation:
Let's use the first law of thermodynamics
ΔE = Q + W
in this case the cylinder is insulated, so there is no heat transfer
ΔE = W
internal energy can be related to the change in temperature
ΔE = 3/2 n K ΔT
we substitute
3/2 n (T₂-T₁) = W
as the work is on the gas it is negative
W = 3/2 n (T₁- T₂)
5. Charges added to a conductor quickly spread over the surface of the object.
a. True
b. False
Answer:
a. True
Explanation:
Conduction involves the transfer of electric charge or thermal energy due to the movement of particles. When the conduction relates to electric charge, it is known as electrical conduction while when it relates to thermal energy, it is known as heat conduction.
A conductor can be defined as any material or physical object that allows the conduction (transfer) of electric charge or thermal energy. Some examples of conductors are metal, steel, aluminum, copper, frying pan, pot, metallic spoon, etc.
During heat conduction, thermal energy is usually transferred from fast moving particles to slow moving particles during the collision of these particles.
Furthermore, any charge that is added to a conductor would quickly spread over the surface of the conducting object due to the fact that it allows the movement of subatomic particles.
Answer: True
Explanation: Aced Test
What is the first quantum number of a 252 electron in phosphorus,
1322s22p3s23p3?
A. n=0
B. n= 3
O
C. n = 1
O D. n = 2
Answer:
the correct answer is B
Explanation:
The quantum numbers are the constants obtained when solving the Schrodinger equation, the first quantum number or principal quantum number (n), can take values from zero to infinity.
This quantum number is placed as a coefficient in the quantum distribution.
In this case for phosphorus, the number is n = 3
the correct answer is B
Jesse drives 120km to a farm. His trip takes 2 1/2 hoursWhat is his speed?
Speed = distance / time
Speed = 120 km / 2 1/2 hours
Speed = 48 km per hour