Answer:
Power = 124.50 W
Explanation:
Given that:
The Sound intensity of a speaker output is 102 dB
and the distance r = 25 m
For the intensity of sound,
[tex]\beta (dB)= 10 \ log_{10 } (\dfrac{I}{I_o})[/tex]
where;
the threshold of hearing [tex]I_o = 10^{-12} (W/m^2)[/tex]
[tex]\dfrac{102 }{10}= log_{10}( \dfrac{I}{10^{-12}})[/tex]
[tex]10^{10.2} = \dfrac{I}{10^{-12}}[/tex]
[tex]I = 10^{10.2} \times 10^{-12}[/tex]
I = 0.01585 W/m²
If we recall, we know remember that ;
Power = Intensity × A rea
Power = 0.01585 W/m² × 4 × 3.142 × (25 m)²
Power = 124.50 W
A 75kg man climbs the stairs to the fifth floor of a building. A total hieght of 16m. His potential energy has increased by
Answer:
11760 joules
Explanation:
Given
Mass (m) = 75kg
Height (h) = 16m
Required
Determine the increment in potential energy (PE)
This is calculated as thus:
PE = mgh
Where g = 9.8m/s²
Substitute values for m, g and h.
P.E = 75 * 9.8 * 16
P.E = 11760 joules
The potential energy of the man in the fifth floor of the building has increased by 11760J.
Given the data in the question;
Mass of the man; [tex]m = 75kg[/tex]Height; [tex]h = 16m[/tex]Potential energy; [tex]P_E =\ ?[/tex]
Potential energy is the energy possessed by a particle due to its position relative to other particles. It is expressed as:
[tex]P_E = mgh[/tex]
Where m is mass of the particle, h is its height above ground level and g is acceleration due to gravity( [tex]g = 9.8m/s^2[/tex] ).
We substitute our values into the equation
[tex]P_E = 75kg\ *\ 9.8m/s^2\ *\ 16m\\\\P_E = 11760kg.m/s^2\\\\ P_E = 11760J[/tex]
Therefore, the potential energy of the man in the fifth floor of the building has increased by 11760J.
Learn more: https://brainly.com/question/16850959
D
5. Mariam driving at a speed of 20.0 m/s applies
brakes close to a signal and travels a distance of
200 m before coming to rest. What was her
acceleration?
A. -0.50 m/s2
B. -0.70 m/s2
C. -1.00 m/s2
D. -2.00 m/s2
6. A trollen at rest is nushed to accelerate at a
Answer:
maibi.... D
Explanation:
I think is D
What do mammoths and tigers need energy for
what to do if the patient stops breaching during Fainting ?
Answer:
unloosen the tight attire parts,open all windows for better air circulation,if he/she does not react place your hands on the chest and press gently three times per interval while giving them air through the mouth CPR then when they react place them to lie horizontal face sideways
A hiker walks 11 km due north from camp and then turns and walks 11 km due east.
What is the total distance walked by the hiker?
What is the displacement (on a straight line) of the hiker from the camp?
please answer all questions
Please help
A student plans an investigation to determine the refractive index of glass. The student uses this equipments.
- a ray box
- a rectangular glass block
- a protractor
- a pencil
Describe how the student collect her data.
Find the magnitude of the net force exerted on the loop by the magnetic field created by the long wire. Answer in units of N.
The question is incomplete. Here is the complete question.
A current in the long, straight wire, which lies in the plane of rectangular loop, that also carries a current, as shown in the figure.
Find the magnitude of the net force exerted on the loop by the magnetic field created by the long wire. Answer in units of N.
Answer: Net Force = [tex]50.215.10^{-7}[/tex]N
Explanation: Force and Magnetic field are related through the following formula:
F = I.L.B.sinθ
Magnetic field (B) in a straight long wire is given by
[tex]B=\frac{\mu_{0}.I}{2.\pi.r}[/tex]
in which
[tex]\mu_{0}[/tex] is permeability of free space and is [tex]4.\pi.10^{-7}[/tex]T.m/A
I is current in the wire;
r is distance to the wire;
Examining the square loop and using the right hand rule, the top, which we will name it F₂, and the bottom, named F₄, have angle θ = 0, giving sin(0) = 0 and therefore, F₁ = F₃ = 0.
So, for the net force, the relevant forces will be on the sides parallel to the wire.
For the other forces, angle is 90°, sin(90°) = 1, then:
F = I.L.B
Replacing magnetic field:
F = [tex]\frac{\mu_{0}.I_{w}.L.I_{l}}{2.\pi.r}[/tex]
Note: The side closest to the wire is F₁, while the farthest is F₃.
Note2: As the constant unit is in meters, distance and length of side of the square loop are also in meters.
Calculating forces:
F₁ = [tex]\frac{4*\pi*10^{-7}*4.3*0.19*14}{2.\pi.0.082}[/tex]
F₁ = [tex]278.975*10^{-7}[/tex]N
Current in F₃ is flowing thoruhg the negative side of the referential, so:
F₃ = [tex]-\frac{4*\pi*10^{-7}*4.3*0.19*14}{2.\pi.0.1}[/tex]
F₃ = [tex]-228.76*10^{-7}[/tex]N
Net force is total force:
[tex]F_{net} = F_{1}+F_{3}[/tex]
[tex]F_{net}=(278.975-228.76).10^{-7}[/tex]
[tex]F_{net}=50.22.10^{-7}[/tex]
The total force acting on the square loop is [tex]F_{net}=50.22.10^{-7}[/tex]N.
A sound wave can be considered as a displacement wave or a pressure wave? What phase difference exists between the displacement and the pressure of a sound wave?
N₂ + H₂
NH3
how do i balance this equation?
Answer:
N2 + 3H2 -----> 2NH3
Explanation:
Reactants side:
2 Nitrogen
5 Hydrogen
Products Side:
2 Nitrogen
5 Hydrogen
What is the solution?
Answer:
1) x = 30 - 8 t
2) x = -10
3) x = -10 + 5 t
4) x = -10 - 4 t
Explanation:
Motion 1: constant negative velocity calculated via the points (0, 30) and (5, -10) rendering the equation of motion x = 30 - 8 t
Motion 2: constant position over time, so the object is not moving, and the equation of motion is x = -10
Motion 3: constant positive velocity estimated via the points (0, -10) and (2, 0), and the equation of motion is: x = -10 + 5 t
Motion 4: constant negative velocity estimated via the points (0, -10) and (5, -30), and the equation of motion is: x = -10 - 4 t
The starting position of motion 1 is 30 meters
the starting position for the other 3 motions is - 10 meters. And none of them is accelerated (acceleration = zero for all).
The plate is a model for how sunlight hits Earth’s surface. Which parts of Earth are most similar to the plate with an axis angle of 0°?
Answer: The parts closer to the equator.
Explanation:
The parts of the earth closer to the equator are similar to the plate, because they receive more sunlights than other parts. Which makes them hotter than any other regions in the earth. Example of such countries are Gabon, Uganda, Kenya, Maldives, the democratic republic of Congo, sao tome and principle e.t.c
In the analytical method, we use the Pythagorean theorem to find the magnitude of the resultant because ____.
Answer:
it obeys the law of vector addition
Explanation:
In the analytical method, we use the Pythagorean theorem to find the magnitude of the resultant because it obeys the law of vector addition.
The resultant of two vectors A and B is given by;
R' = A' + B'
[tex]R = \sqrt{A^2 + B^2}[/tex]
Therefore, Pythagorean theorem is used if the two quantities are vectors and vector quantities obey the law of vector addition.
What is the density of a 700 kg object with a volume of 649 m3
The Jamaican Bobsled Team is sliding down a hill in a toboggan at a rate of 5 m/s when he reaches an even steeper slope. If he accelerates at 2 m/s2 for the 5 m slope, how fast is he traveling when he reaches the bottom of the 5 m slope?
Answer:
6.7 m/s
Explanation:
Given:
Δx = 5 m
v₀ = 5 m/s
a = 2 m/s²
Find: v
v² = v₀² + 2aΔx
v² = (5 m/s)² + 2 (2 m/s²) (5 m)
v = 6.7 m/s
An empty cup weighs 14 g. The same cup filled with ice cream weighs 120 g. All of the ice cream melts before anyone eats it.
What is the weight of the melted ice cream?
A.0 g
B. 14 g
C. 106 g
D. 134 g
Answer:
D
Explanation:
What's the difference between an open cluster and a globular cluster
An open cluster is a group of up to a few thousand stars that were formed from the same giant molecular cloud, and are still loosely gravitationally bound to each other. In contrast, globular clusters are very tightly bound by gravity. ... Open clusters are very important objects in the study of stellar evolution.
One strategy in a snowball fight is to throw
a snowball at a high angle over level ground.
While your opponent is watching this first
snowball, you throw a second snowball at a
low angle and time it to arrive at the same
time as the first.
Assume both snowballs are thrown with
the same initial speed 16.2 m/s. The first
snowball is thrown at an angle of 62° above
the horizontal. At what angle should you
throw the second snowball to make it hit the
same point as the first? Note the starting and
ending heights are the same. The acceleration
of gravity is 9.8 m/s.
second question: How many seconds after the first snowball
should you throw the second so that they
arrive on target at the same time?
Answer in units of s.
Answer:
Part 1: 28°
Part 2: 1.367
Explanation:
Part 1:
Given: 62°
Simple
θ = 90°- 62°
θ = 28°
Part 2:
Y-direction
Δy[tex]=v_{yo} t+\frac{1}{2} a_{y} t^{2}[/tex]
[tex]0=[16.2sin(62)]t_{1}+1/2(-9.8)t_{1}^{2} \\[/tex]
[tex]t_{1} =\frac{2[16.2sin(62)]}{9.8}[/tex]
[tex]t_{1}=2.91913s[/tex]
[tex]0=[16.2sin(28)]t_{2}+1/2(-9.8)t_{2}^{2}[/tex]
[tex]t_{2} =\frac{2[16.2sin(28)]}{9.8}[/tex]
[tex]t_{2}=1.55213s[/tex]
Δt[tex]=t_{1}-t_{2}[/tex]
Δt[tex]=2.91913-1.55213[/tex]
Δt= 1.367s
Hope it helps :)
3.what does this stand for ??
Answer:
see below
Explanation:
The triangle stands for the change in
We would change the change in x
Answer:
Δ This is the symbol of Delta which means Change
and x is length/distance/position.
Thus, Δx stands for Change in length/distance/position.
-TheUnknownScientist
The interaction between electrical energy and magnetism has been an important
topic in 20th century science, Which term describes this interaction?
Answer:
Maybe
Explanation:
I say maybe because it will help them still but not quite
An 11 kg toddler is running at a speed of 8 m/s. How much energy does he have?
Please help
Answer:g
Explanation:jqjqksk
plzzz helppp
You are pushing a box North in the hallway, at 20n, and a friend gets in front of the box and goes in the opposite direction, at 30n. What direction is the box going at? How much force does the box have going in that direction?
Answer:
the box is going south at 10n
Explanation:
You have made a simple circuit with one bulb. If you wanted to add an
extra bulb without the first bulb dimming. What would you need to
design?
A. A series circuit
B. A complex circuit
C. A parallel circuit
D. An incomplete circuit
Answer:
[tex]A. \: A \: series \: circuit[/tex]
Explanation:
♨Rage♨
Answer:
C. A parallel circuit
Explanation:
Adding a bulb in parallel with the existing bulb will apply the same voltage to both bulbs. They will light equally bright.
You would design a parallel circuit.
_____
In a series circuit the same current would flow in both bulbs, but that current would be at half the original current level. Both bulbs would be dimmer than the first bulb was.
It is difficult to create a "complex" circuit with only two components. An "incomplete" circuit would result in no light at all.
2. A bird flying horizontally at 10 m/s drops a branch. The bird is flying at an altitude of 20 m. Determine
the horizontal displacement it moves relative to where it was dropped.
Answer:
The horizontal displacement is 20 m.
Explanation:
Given that,
Velocity = 10 m/s
Height = 20 m
We need to calculate the time
Using equation of motion
[tex]s=ut+\dfrac{1}{2}gt^2[/tex]
Put the value into the formula
[tex]20=0+\dfrac{1}{2}\times9.8\times t^2[/tex]
[tex]t^2=\dfrac{20\times2}{9.8}[/tex]
[tex]t=\sqrt{\dfrac{20\times2}{9.8}}[/tex]
[tex]t=2.0\ sec[/tex]
We need to calculate the horizontal displacement
Using formula of horizontal displacement
[tex]\Delta x=v_{x}\times t[/tex]
Put the value into the formula
[tex]\Delta x=10\times2.0[/tex]
[tex]\Delta x=20\ m[/tex]
Hence, The horizontal displacement is 20 m.
A 75 Kg skateboarder is riding downhill, exerting 25 N. What is their acceleration?
Answer:
[tex]a=0.33\frac{m}{s^2}[/tex]
Explanation:
Hello.
In this case, since the force is defined in terms of the mass and acceleration as follows:
[tex]F=ma[/tex]
Given the force and the mass, we can compute the acceleration as shown below:
[tex]a=\frac{F}{m}=\frac{25N}{75kg}=\frac{25kg\frac{m}{s^2} }{75kg}\\ \\a=0.33\frac{m}{s^2}[/tex]
Best regards.
An object at rest starts accelerating.
If it travels 20 meters to end up going 10 m/s.
what was its acceleration?
Variables:
Equation and Solve:
Answer:
We are given:
initial velocity (u) = 0 m/s
final velocity (v) = 10 m/s
displacement (s) = 20 m
acceleration (a) = a m/s/s
Solving for 'a'
From the third equation of motion:
v² - u² = 2as
replacing the variables
(10)² - (0)² = 2(a)(20)
100 = 40a
a = 100 / 40
a = 2.5 m/s²
describe the energy conversion that occurs in a diesel engine
Consider a particle of mass m which can move freely along the x axis from -a/2 to a/2, but which is strictly prohibited from being found outside this region. The wave function of the particle within the allowed region is
Answer:
φ = B sin (2π n/a x)
Explanation:
In quantum mechanics when a particle moves freely it implies that the potential is zero (V = 0), so its wave function is
φ = A cos kx + B sin kx
we must place the boundary conditions to determine the value of the constants A and B.
In our case we are told that the particle cannot be outside the boundary given by x = ± a / 2
therefore we must make the cosine part zero, for this the constant A = 0, the wave function remains
φ = B sin kx
the wave vector is
k = 2π /λ
now let's adjust the period, in the border fi = 0 therefore the sine function must be zero
φ (a /2) = 0
0 = A sin (2π/λ a/2)
therefore the sine argument is
2π /λ a/2 = n π
λ= a / n
we substitute
φ = B sin (2π n/a x)
A car travels at a velocity of 80 m/s, accelerates than stops in 250 second. What is the acceleration of the truck?
(I’ll give brainliest please someone help me on this and explain it with work I don’t get it)
True.or false A railroad track runs southwest to northeast.
Answer:
ns for high-speed rail in the United States date back to the High Speed Ground Transportation Act of 1965. Various state and federal proposals have followed. Despite being one of the world's first countries to get high-speed trains (the Metroliner service in 1969), it failed to spread. Definitions of what constitutes high-speed rail vary, including a range of speeds over 110 mph (180 km/h) and dedicated rail lines. Inter-city railwith top speeds between 90 and 125 mph (140 and 200 km/h) is sometimes referred to in the United States as higher-speed rail.[1]
Amtrak's Acela Express (reaching 150 mph, 240 km/h), Silver Star, Northeast Regional, Keystone Service, Vermonter and certain MARC Penn Line express trains (all five reaching 125 mph, 201 km/h) are the only high-speed services in the country.
As of 2020, the California High-Speed Rail Authority is working on the California High-Speed Rail project and construction is under way on sections traversing the Central Valley. The Central Valley section is planned to open in 2029 and Phase I is planned for completion in 2031.[2]
Contents
1 Definitions in American context
2 History
2.1 Faster inter-city trains: 1920–1941
2.2 Post-war period: 1945–1960
2.3 First attempts: 1960–1992
2.4 Renewed interest: 1993–2008
2.5 Plans for 2008–2013
3 Current state and regional efforts
3.1 The Northeast
3.1.1 Northeast Corridor: Next Generation High-Speed Rail
3.1.1.1 Proposed routes
3.1.2 Northeast Maglev proposal
3.1.3 New Jersey–New York City upgrades
3.1.4 New York
3.1.5 Pennsylvania
3.2 Western States
3.2.1 California
3.2.2 Pacific Northwest
3.2.3 Arizona
3.3 Mid-Atlantic and the South
3.3.1 Florida
3.3.2 Southeast
3.3.3 Texas
3.4 Midwest
3.4.1 Illinois and the Midwest
3.5 The Southwest
4 Federal high-speed rail initiatives
4.1 American Recovery and Reinvestment Act of 2009
4.1.1 Strategic plan
4.2 2009 federal grant funding
4.3 2010 allocation
4.3.1 Cancellation of funds for Wisconsin, Ohio, and Florida
4.4 2011 and 2012 proposals and rejections of funding
5 See also
6 Notes
7 Further reading
8 External links
Explanation:
block of mass m sits at rest on a rough inclined ramp that makes an angle with the horizontal. What must be true about normal force F on the block due to the ramp
Answer:
Explanation:
For a body on a ramp with mass m, the forces acting on the body along the vertical component are the weight and the normal reaction.
The weight of the body acts in the negative y direction while the normal reaction acts in the positive y direction
Taking the sum of forces along the y component
Sum Fy = -W+R = ma
Since acceleration is zero
-W+R = m(0)
-W+R = 0
-W = -R
W = R
Hence the Normal reaction force acting on the on the body is equal to normal force