A designer is creating an obstacle for an obstacle course where a person starts on a moveable platform of height H from the ground. The person grabs a rope of length L and swings downward. At the instant the rope is vertical, the person lets go of the rope and attempts to reach the far side of a water-filled moat. The left side of the moat is directly below the position where the person will let go of the rope. The designer runs several tests in which the rope has different lengths and moves the platform such that the rope is always initially horizontal. The designer notices that the person cannot land on the other side if the length L is very short. The designer also notices that the person also cannot land on the other side if the length L is very close to the height H.
Assume the size of the person is much smaller than the lengths L and H. Let D represent the horizontal distance from below the release point to where the person lands.
Required:
a. Why does the person land in the moat if the rope's length is very short?
b. Why does the person land in the moat if the length is nearly the same as the height of the platform?
Answers
Answer:
* when L → H chord too long
in this case we see that the speed to cross the well grows a lot (it goes towards infinity) therefore we do not have enough speed in the movement to cross
* when L → 0 very short string
the speed of the platform is very small, so we do not have the minimum required value
vox = √ (g / (2 (H)) D
Explanation:
For this exercise we are going to solve it using conservation of energy to find the velocity of the body and the launch of projectiles to find the velocity to cross the well.
Let's start with the projectile launch
as the body leaves the vertical its velocity must be horizontal
x = v₀ₓ t
y = y₀ + [tex]v_{oy}[/tex] t - ½ g t²
when reaching the ground its height of zero (y = 0) and the initial vertical velocity is zero
t = √ 2 y₀ / g
we substitute
x = vox √2y₀ / g
v₀ₓ = √(g / 2y₀) x
In the exercise, it tells us that the width of the well is D (x = D) and the initial height is the height of the platform minus the length of the rope (I = H - L)
v₀ₓ = √(g /(2 (H -L)) D
this is the minimum speed to cross the well.
Now let's use conservation of energy
starting point. On the platform
[tex]Em_{o}[/tex] = U = m g H
final point. At the bottom of the swing
Em_{f} = K + U = 1 / 2m v² + m g (H -L)
as there is no friction the mechanical energy is conserved
Em_{o} = Em_{f}
m g H = 1 / 2m v² + m g (H -L)
v = √ (2gL)
let's write our two equations
the minimum speed to cross the well
v₀ₓ = √ (g /(2 (H -L)) D
the speed at the bottom of the oscillatory motion
v = √ (2g L)
we analyze the extreme cases
* when L → H chord too long
in this case we see that the speed to cross the well grows a lot (it goes towards infinity) therefore we do not have enough speed in the movement to cross
* when L → 0 very short string
the speed of the platform is very small, so we do not have the minimum required value
vox = √ (g / (2 (H)) D
From this analysis we see that there is a range of lengths that allows us to have the necessary speeds to cross the well
V₀ₓ = v
g / (2 (H -L) D² = 2g L
4 L (H- L) = D²
4 H L - 4 L2 - D² = 0
L² - H L - D² / 4 = 0
let's solve the quadratic equation
L = [H ± √ (H2-D2)] / 2
we assume that H> D
L = ½ H [1 + - RA (1 - (D / H) 2)]
The two values of La give the range of values for which the two speeds are equal
A) The person lands in the moat if the rope's length is very short because :
The speed of the platform is less than the required minimum speedB) The person lands in the moat if the rope length is similar to the height of the platform because :
The speed required to cross the moat approaches infinityFollowing the assumptions;
size of the person is much smaller than L and H
D = horizontal distance
The conditions that will cause the person to land on the moatThe person will land in the moat when the rope's length is very short because as the rope reduces in length the speed reduces as well such that the speed of the platform goes below the required minimum speed which will enable the person cross over. while As the magnitude of the length tends towards the same magnitude of the height the speed required to cross the moat increases towards infinity and this speed cannot be attained by the person hence he will land in the moat.Hence we can conclude that The person lands in the moat if the rope's length is very short because The speed of the platform is less than the required minimum speed and The person lands in the moat if the rope length is similar to the height of the platform because,the speed required to cross the moat approaches infinity.
Learn more about obstacle course : https://brainly.com/question/241926
Related Questions
Notice that the electromagnet in the virtual simulation is made up of a battery and a wire. What item could you add to the electromagnet to make it even stronger?
Answers
Answer:
Explanation:
Have y’all seen steeleflag19 at all on here?
A car starts from rest and accelerates for 7.2 s with an acceleration of 1.4 m/s2. How far does it travel? Answer in units of m.
Answers
Answer:
xn = 36.28 [m]
Explanation:
To solve this problem we must use the following equation of kinematics, which is ideal for a body that moves with constant acceleration.
[tex]x=x_{0}+(v_{o} *t)+(\frac{1}{2} )*a*t^{2}[/tex]
where:
x - xo = displacement of the car [m]
Vo = initial velocity = 0
t = time = 7.2 [s]
a = acceleration = 1.4 [m/s^2]
The initial velocity is zero, as the car begins its movement from rest.
xn = (x - xo), Now replacing
xn = (0*7.2) + 0.5*1.4*(7.2^2)
xn = 36.28 [m]
It took 50 joules to push a chair 5 meters across the floor. With what force was the chair pushed?
Answers
Answer:
The chair was pushed with 10 N.
Explanation:
The chair was pushed with 50 Joules.
Work = Force * Distance
50 J = F * 5m
F = 50 / 5 = 10N
The chair was pushed with 10 N.
The chair was pushed with 10 N force.
What is Work done?Work is defined as the measure of energy transfer that occurs when an object is moved over a distance by an external force, at least part of which is applied in the direction of displacement.
If the force is constant then work can be calculated by multiplying the length of the path by the component of the force acting along the path, which is expressed mathematically as work W equal to the force f over a distance d, or W = fd.
So, for above given information,
Work done= 50 joules
Distance covered by the chair = 5m
Then, Force= W/d
=50/5= 10N
Thus, the chair was pushed with 10 N force.
Learn more about Work done, here:
https://brainly.com/question/13662169
#SPJ2
A "lovesick" individual wants to throw a bag of candy and love notes into the open window of their significant other’s bedroom 10.0 m above. Assuming it just reaches the window, they throw the gift at 60.0o to the ground: At what velocity should they throw the bag? How far from the house are they standing when they throw the bag? (Answer: A. 16.2m/s B. 11.5m)
Answers
Answer:
Explanation:
Let the velocity be v .
vertical component of the velocity = v sin 60 = √3 v /2
it reaches maximum height of 10 m .
v² = 2 gh
( √3 v/2 )² = 2 x 9.8 x 10
3 v² = 196 x 4
v² = 65.33 x 4
v = 16.2 m /s
Let time taken to reach height of 10 m
v = u - gt
v sin 60 = 9.8 t
16.2 x √3 /2 = 9.8 t
t = 1.43 s
horizontal distance covered = v cos 60 x t
16.2 x .5 x 1.43 = 11 .5 m
True.or false A railroad track runs southwest to northeast.
Answers
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:
If we assume their arms are each 0.90 m long and their individual masses are 65.0 kg , how hard are they pulling on one another
Answers
Complete Question
On an ice rink two skaters of equal mass grab hands and spin in a mutual circle once every 2.7 s .
If we assume their arms are each 0.90 m long and their individual masses are 65.0 kg , how hard are they pulling on one another?
Answer:
The force is [tex]F = 316.8 \ N[/tex]
Explanation:
From the question we are told that
The period is T = 2.7 s
The radius of the circle formed by their arms is r = 0.90 m
Their individual mass is [tex]m = 65.0 \ kg[/tex]
Generally their angular velocity is mathematically represented as
[tex]w = \frac{2 \pi}{T}[/tex]
=> [tex]w = \frac{2 * 3.142 }{2.7}[/tex]
=> [tex]w =2.327 \ rad/ s [/tex]
Generally the pulling force is mathematically represented as
[tex]F = m * w ^2 * r[/tex]
=> [tex]F = 65 * 2.327^2 * 0.90[/tex]
=> [tex]F = 316.8 \ N[/tex]
The acceleration of the spacecraft in which the Apollo astronauts took off from the moon was 3.4 m/s2 m / s 2 . On the moon, g g = 1.6 m/s2 m / s 2 . what's the apparent weight
Answers
Complete Question
The acceleration of the spacecraft in which the Apollo astronauts took off from the moon was 3.4 m/s2. On the moon, g = 1.6 m/s2. What was the apparent weight of a 75 kg astronaut during takeoff?
Answer:
The value is [tex]N = 375 \ N[/tex]
Explanation:
From the question we are told that
The acceleration is [tex]a = 3.4 \ m/s^2[/tex]
The acceleration due to gravity in the moon is [tex]g = 1.6 m/s^2[/tex]
The mass of the astronaut is [tex]m = 75 \ kg[/tex]
Generally the apparent weight is mathematically represented as
[tex]W = ma + mg[/tex]
=> [tex]W = 3.4 * 75 + 1.6 * 75[/tex]
=> [tex]W = 375 \ N[/tex]
How long would it take you to walk 3,962 km from New York to Los
Angeles?
Answers
Answer:
913 hours ur welcome :)
A vector of components (−23, −22) is multiplied by the scalar value of −6. What is the magnitude and direction of the resultant vector?
Answers
Answer:
(1,)
Explanation:
Answer:
magnitude: 21.6; direction: 33.7°
Explanation:
Someone help
Match the definition to the term.
1.
the noun that follows the verb and answers the questions
whom or what
linking verb
2. a word that expresses action
sentence
3. who or what the sentence is about
predicate noun
4.
a noun that indicates to or for whom or what something is
done
predicate adjective
5. follows a linking verb and renames the subject
direct object
subject
6. follows a linking verb and describes a subject
verb that joins a subject and a predicate noun or predicate
7.
adjective
indirect object
8. expresses a complete thought
verb
Answers
Answer:
Explanation:
No 1 is linked to the option provided at no 5.
A direct object is the noun that follows the verb and answers the question.
No 2 is linked to the option provided at no 8.
A verb is a word that expresses action.
No 3 is linked to the option provided at no 5.
The subject is what or whom the sentence is about.
No 5 is linked to the option provided at no 3.
A predicate noun follows a linking verb, and renames the subject.
No 6 is linked to the option provided at no 4.
A predicate adjective follows a linking verb, and describes a subject.
No 7 is linked to the option provided at no 1.
A linking verb joins a subject and a predicate.
No 8 is linked to the option provided at no 2.
A sentence expresses a complete thought....
Answer:
predicate noun: follows a linking verb and describes a subject
verb: a word that expresses action
direct object: a noun that indicates to or for whom or what something is done
sentence: expresses a complete thought
predicate adjective: verb that joins a subject and a predicate noun or predicate adjective
subject: who or what the sentence is about
indirect object: follows a linking verb and renames the subject
linking verb: the noun that follows the verb and answers the questions whom or what
Hope this helps!
Correct me if I'm wrong:)
What is the solution?
Answers
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).
At a certain instant, a proton is moving in the positive x direction through a magnetic field in the negative z direction. What is the direction of the magnetic force exerted on the proton
Answers
Answer: positive y direction
Explanation:
we know that direction of velocity is in +x direction
now the magnetic force is in negative z direction
therefore the magnetic force , F = q × ( v × B)
F = ( i × [ - k ] ) direction
F = j direction
so the direction of the magnetic force on the proton is positive y direction.
The bandgap of InP semiconductor laser is 1.0 eV. The effective mass of the valence band is ½ of the effective mass of the conduction band. Assuming that electron hole recombination transition occurs at 0.03 eV above the bandgap, calculate the wavelength of this transition.
Answers
Answer: the wavelength of this transition is 1.2039 um
Explanation:
Given that;
the energy level between the transitioning energy gap Eg = 1.0 + 0.03 = 1.03 eV
we know that λ = 1.24 / Eg
so we substitute our Eg into the above equation
λ = 1.24 / 1.03
λ = 1.2039 um
therefore the wavelength of this transition is 1.2039 um
Write a function to accept a vector of masses (m) from the user and gives the corresponding energy to them. Energy vector is the output of the program. Constant c is the speed of light which is 2.9979 x 108 m/s inside the function.
Answers
Answer:
Written in Python
def energyvector(mass):
c = 2.9979 * 10**8
energy = mass * c ** 2
print(round(energy,2))
Explanation:
This line defines the function
def energyvector(mass):
This line initializes the speed of light
c = 2.9979 * 10**8
This line calculates the corresponding energy
energy = mass * c ** 2
This line prints the calculated energy
print(round(energy,2))
which equation should be used to find speed
Answers
Answer:
The formula for speed is speed = distance ÷ time. To work out what the units are for speed, you need to know the units for distance and time. In this example, distance is in metres (m) and time is in seconds (s), so the units will be in metres per second (m/s).
how are s waves and p waves simuliar?
A.they shake the ground
B.they travel through liquids
C. they arrive at the same time
D.they shake the ground from side to side
Answers
Answer:
A
Explanation:
hope this helps
A jet plane lands with a speed of 100 m/s and can
accelerate at a maximum rate of 5.00 m/s2 as it comes to
rest. (a) From the instant the plane touches the runway,
what is the minimum time needed before it can come to
rest? (b) Can this plane land on a small tropical island
airport where the runway is 0.800 km long?
Answers
Answer:
a) t = 20 [s]
b) Can't land
Explanation:
To solve this problem we must use kinematics equations, it is of great importance to note that when the plane lands it slows down until it reaches rest, ie the final speed will be zero.
a)
[tex]v_{f}=v_{i}-(a*t)[/tex]
where:
Vf = final velocity = 0
Vi = initial velocity = 100 [m/s]
a = desacceleration = 5 [m/s^2]
t = time [s]
Note: the negative sign of the equation means that the aircraft slows down as it stops.
0 = 100 - 5*t
5*t = 100
t = 20 [s]
b)
Now we can find the distance using the following kinematics equation.
[tex]x -x_{o}=(v_{o}*t)+\frac{1}{2}*a*t^{2}[/tex]
x - xo = distance [m]
x -xo = (0*20) + (0.5*5*20^2)
x - xo = 1000 [m]
1000 [m] = 1 [km]
And the runaway is 0.8 [km], therefore the jetplane needs 1 [km] to land. So the jetpalne can't land
PLS HELP 3. Which graph best represents the relationship between acceleration due to gravity and mass for
objects near the surface of Earth? [Neglect air resistance.)
Acceleration
Answers
This question involves the concepts of mass, acceleration due to gravity, weight, Newton's Gravitational Law, gravitational force, and graphs.
Graph "A" re[resents the best relationship between acceleration due to gravity, and mass for objects.
The relationship between the mass of earth and the acceleration due to gravity can be found by equating the weight of the object and the gravitational force, from Newton's Gravitational Law on it:
[tex]Weigth = Gravitational\ Force\\\\mg = \frac{GmM}{r^2}\\\\g = \frac{GM}{r^2} ---------- eqn(1)[/tex]
where,
g = acceleration due to gravity
G = universal gravitational constant
M = mass of Earth
r = radius of Earth
Hence, it is clear from equation (1), that mass of the Earth and the acceleration due to gravity have a direct relationship with each other. Therefore the graph between them will be a straight line, which is Graph A.
Learn more about Newton's Law of Gravitation here:
brainly.com/question/17931361?referrer=searchResults
The attached picture illustrates Newton's Law of Gravitation.
Problem 9.23 A uniform-density 8 kg disk of radius 0.21 m is mounted on a nearly frictionless axle. Initially it is not spinning. A string is wrapped tightly around the disk, and you pull on the string with a constant force of 36 N through a distance of 0.9 m. Now what is the angular speed?
Answers
Answer:
4.63rad/s
Explanation:
The centripetal force is expressed as;
F = mv²/r
M is the mass of the disk = 8kg
v is the linear speed = wr
r is the radius = 0.21m
Force = 36N
Write the force in term of the angular velocity
F = m(wr)²/r
F = mw²r²/r
F = mw²r
36 = 8w²(0.21)
36 = 1.68w²
w² = 36/1.68
w² = 21.43
w = √21.43
w = 4.63rad/s
Hence the angular speed is now 4.63rad/s
R=(4.7)^2+(6.6)^2-2.(4.7)+(6.6).(180-45)
Answers
Answer:
I have no clue what this means or what the answer is i am just trying to get my points up so i can ask questions
Explanation:
i am going to put something here so it looks like an explanation so yeah this has no meaning whatsoever i am very sorry that i am not able to give you the answer try looking the answer up im very very very very sorry :(
A stereo speaker is rated at P1000 = 52 W of output at 1000 Hz. At 20 Hz, the sound intensity level LaTeX: \betaβ decreases by 1.3 dB. What is the power output P
Answers
Answer:
The value of the power is [tex]P_c = 38.55 \ W [/tex]
Explanation:
From the question we are told that
The power rating [tex]P_{1000} =P_b= 52 \ W[/tex]
The frequency is [tex]f = 1000 \ Hz[/tex]
The frequency at which the sound intensity decreases [tex]f_k = 20 \ Hz[/tex]
The decrease in intensity is by [tex]\beta = 1.3 dB[/tex]
Generally the initial intensity of the speaker is mathematically represented as
[tex]\beta_1 = 10 log_{10} [\frac{P_b}{P_a} ][/tex]
Generally the intensity of the speaker after it has been decreased is
[tex]\beta_2 = 10 log_{10} [\frac{P_c}{P_a} ][/tex]
So
[tex]\beta_1-\beta_2 = 10 log_{10} [\frac{P_c}{P_a} ]- 10 log_{10} [\frac{P_b}{P_a} ][/tex]
=> [tex]\beta = 10 log_{10} [\frac{P_c}{P_a} ]- 10 log_{10} [\frac{P_b}{P_a} ]= 1.3[/tex]
=> [tex]\beta =10log_{10} [\frac{\frac{P_b}{P_a}}{\frac{P_c}{P_a}} ] = 1.3[/tex]
=> [tex]\beta =10log_{10} [\frac{P_b}{P_c} ] = 1.3[/tex]
=> [tex]10log_{10} [\frac{P_b}{P_c} ] = 1.3[/tex]
=> [tex]log_{10} [\frac{P_b}{P_c} ] = 0.13[/tex]
taking atilog of both sides
[tex][\frac{P_b}{P_c} ] = 10^{0.13}[/tex]
=>[tex][\frac{52}{P_c} ] = 10^{0.13}[/tex]
=> [tex]P_c = \frac{52}{1.34896}[/tex]
=> [tex]P_c = 38.55 \ W [/tex]
what to do if the patient stops breaching during Fainting ?
Answers
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
how much min the basketball 1 player play
Answers
Answer:
A professional basketball game depends on the association presiding over the game. An NBA game lasts for 48 minutes whereas FIBA games take 40 minutes. The total time taken to play for any specialized game is over 2 hours 15 minutes. The time includes the time disruptions like fouls, timeouts, and breaks.
I hope it helps you...
A tightly wound solenoid is 15 cm long, has 350 turns, and carries a current of 4.0 A. If you ignore end effects, you will find that the value of app at the center of the solenoid when there is no core is approximately
Answers
Answer:
The magnetic field at the center of the solenoid is approximately 0.0117 T
Explanation:
Given;
length of the solenoid, L = 15 cm = 0.15 m
number of turns of the solenoid, N = 350 turns
current in the solenoid, I = 4.0 A
The magnetic field at the center of the solenoid is given by;
[tex]B = \mu_o (\frac{N}{L} )I\\\\B = (4 \pi *10^{-7})(\frac{350}{0.15} )(4.0)\\\\B = 0.0117 \ T[/tex]
Therefore, the magnetic field at the center of the solenoid is approximately 0.0117 T.
What is Triangle ill send a picture
Answers
.......
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
Answers
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.
a Venus fly trap is an......... plant.
Answers
Answer:
A Venus flytrap is a perennial carnivorous plant.
I hope it helps
plant that eats meat
A person following a liberal ideology would likely approve of
Answers
not sure sorry :5
A balloon is launched straight upward from the edge of a 40 m high cliff with a velocity of 30
m/s. The balloon goes up and barely misses the edge of the cliff on the way down and hits the
ground below.
A.) Determine the overall hang time of the balloon.
B.) How high did the balloon travel above the cliff?
C.) Determine the velocity of the balloon at t = 3 s.
D.) Determine the acceleration of the balloon at t = 3 s.
Answers
Answer:
A) t = 7.25 sec
B) 45.92 m above the cliff and 85.92 m counting from ground level
C) about 0.6 m/s
D) The only acceleration is always that of gravity : 9.8 m/s^2
Explanation:
The kinematic equation for the position as a function of time is:
y = 40 + 30 * t - (g/2) t^2
The total time the balloon was in the air is calculated for when the final position is y = 0 (when it touches the ground), that is:
0 = 40 + 30 * t - (g/2) t^2
0 = 40 +30 t - 4.9 t^2
which can be solved for "t" using the quadratic formula, and which renders two different times "t", of which we pick the positive answer: t = 7.25 sec.
For the maximum height, we estimate the time it takes for the balloon to reach the maximum height at which the velocity is zero (changes direction of motion):
vf = vi - g * t
0 = 30 - 9.8 * t
t = 30 / 9.8 = 3.06 seconds
Now we use this value in our position equation and get:
ymax = 40 + 30 (3.06) - 4.9 (3.06)^2
ymax = 85.92 m (from ground level
Therefore, from the cliff (that is at 40 m height) the height is 85.92 - 40 = 45.92 m.
The velocity of the balloon at t = 3 seconds can be calculated with the velocity expression we have been using:
v(t) = vi - g * t
v(3) = 30 - 9.8 (3) = 0.6 m/s
The only acceleration acting on the balloon is always the acceleration due to gravity (g = 9.8 m/s^2)
What is the speaker’s power output if the sound intensity level is 102 dBdB at a distance of 25 mm ? Express your answer to two significant figures and include the appropriate units.
Answers
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