Answer:
77.6 Hz
Explanation:
What frequency is received by a person watching an oncoming ambulance moving at 115 km/h and emitting a steady 753 Hz sound from its siren.
The given parameters are:
Observer speed = 115 km/h
Source frequency = 753 Hz
Speed of sound = 342 m/s
First convert km/h to m/s
Observer speed = (115 × 1000) / 3600
Observer speed = 31.94 m/s
The frequency received by the person will be:
F = fv / ( V - v )
Where
F = frequency received by the person
f = siren frequency
V = speed of sound
v = speed of the ambulance
Substitute all the parameters into the formula
F = (753 × 31.94) / ( 342 - 31.94 )
F = 24050.82 / 310.06
F = 77.568 Hz
Therefore, the frequency received by a person is approximately 77.6Hz
A falling ball has potential energy of 5 J and a kinetic energy of 10 J. What is the ball's mechanical energy?
A 67.6-kg boy is surfing and catches a wave which gives him an initial speed of 1.56 m/s. He then drops through a height of 1.65 m, and ends with a speed of 8.30 m/s. How much nonconservative work was done on the boy?
Answer:
The nonconservative work was done on the boy is 1154.87 J.
Explanation:
Given;
mass of the boy, m = 67.6 kg
initial speed of the boy, u = 1.56 m/s
height of fall, h = 1.65 m
final speed of the boy, v = 8.30 m/s
The initial energy of the boy is given by;
E₁ = K.E₁ + P.E₁
E₁ = ¹/₂mu² + mgh
E₁ = ¹/₂(67.6)(1.56)² + (67.6 x 9.8 x 1.65)
E₁ = 82.134 + 1091.475
E₁ = 1,173.61 J
The final energy of the boy is given by;
E₂ = K.E₂
E₂ = ¹/₂mv²
E₂ = ¹/₂(67.6)(8.3)²
E₂ = 2,328.482 J
The nonconservative work was done on the boy is given by;
W = E₂- E₁
W = 2,328.482 J - 1,173.61 J
W = 1154.87 J
Therefore, the nonconservative work was done on the boy is 1154.87 J.
I’m so confused someone help
The batter swings his bat 1.8 meters in 0.1 seconds. How fast is his bat speed in meters per second?
Answer:
18 m/s
Explanation:
1.8 meters / 0.1 seconds = 18 m/s
Which theory explains why gravity between two objects changes when the distance between them changes?
Einstein's theory because he suggested that the more distance there is between objects, the more space-time
curves and the greater the strength of gravity is.
Einstein's theory because he suggested that the more distance there is between objects, the more space-time
curves and the weaker the strength of gravity is.
Newton's theory because he suggested that the greater the distance between objects, the greater the pull of gravity.
Newton's theory because he suggested that the greater the distance between objects, the weaker the pull of gravity.
Answer:
Newton's theory because he suggested that the greater the distance between objects, the weaker the pull of gravity.
Answer: The answer is Newton’s theory because he suggested that the greater the distance between objects, the weaker the pull of gravity
Explanation: Just took the test i hope this help you enjoy :D
A spaceship of mass mm circles a planet of mass M in an orbit of radius R. How much energy is required to transfer the spaceship to a circular orbit of radius 3R?
Answer:
ΔE = GmM/3R
Explanation:
The absolute potential energy of an object in a planet's field is given as:
E = -GmM/2r
where,
E = Potential Energy
G = Universal Gravitational Constant
m = mass of spaceship
M = Mass of Planet
r = distance from surface of planet
Therefore, for initial state:
E = E₁ and r = R
E₁ = - GmM/2R
and for final state:
E = E₂ and r = 3R
E₂ = - GmM/6R
So, the required energy will be:
ΔE = E₂ - E₁ = - GmM/6R + GmM/2R
ΔE = GmM(- 1/6R + 1/2R)
ΔE = GmM/3R
A 20kg rock is sliding on a rough, horizontal surface at 8 m/s and eventually stops due to friction. the coefficient of kinetic friction between the rock and the surface is 0.200. what average power is produced by friction as the rock stops?
Answer:
156watts
Explanation:
M = 20
U = 0.200
Vo = 8.0
We are to get p
P = w/t
W = 1/2(vf²-Vo²)
The final velocity is 0
W =-1/2*20*8²
= -640J
Acceleration = -ug
= -0.200*9.8
= -1.96m/s^-2
We are to get t
t = 8/1.96
= 4.1s
P = w/t
= 640/4.1
= 156 watts
156watts is the average power that is produced by friction as the rock stops.
You use an electron microscope in which the matter wave associated with the electron beam has a wavelength of 0.0173 nm. What is the kinetic energy of an electron in the beam, expressed in electron volts?
Answer:
The kinetic energy of an electron in the beam is 5.04 keV.
Explanation:
We need to find the velocity of the electron by using the De Broglie wavelength:
[tex] \lambda = \frac{h}{mv} [/tex]
Where:
λ: is the wavelength = 0.0173 nm
v: is the velocity
m: is the electron's mass = 9.1x10⁻³¹ kg
h: is the Planck constant = 6.62x10⁻³⁴ J.s
[tex] v = \frac{h}{m\lambda} = \frac{6.62 \cdot 10^{-34} J.s}{9.1 \cdot 10^{-31} kg*0.0173 \cdot 10^{-9} m} = 4.21 \cdot 10^{7} m/s [/tex]
Now, we can find the kinetic energy:
[tex] E_{k} = \frac{1}{2}mv^{2} = \frac{1}{2}9.1 \cdot 10^{-31} kg*(4.21 \cdot 10^{7} m/s)^{2} = 8.06 \cdot 10^{-16} J*\frac{1 eV}{1.6 \cdot 10^{-19} J} = 5038 eV = 5.04 keV [/tex]
Therefore, the kinetic energy of an electron in the beam is 5.04 keV.
I hope it helps you!
A plane moves at a speed of 100 mi/h and takes flight on a 25 degree angle. What is the VERTICAL speed in mi/h? Round to the nearest whole number and DO NOT include units (Ex: 11).
Answer:
The vertical speed in mi/h is 42.
Explanation:
Rectangular Components of a Vector
A 2D vector can be expressed in several forms. The rectangular form gives its two components, one for each axis (x,y). The polar form gives the components as (r,θ) being r the magnitude and θ the angle.
The relationships between the coordinates of both systems are shown in the image below.
When the magnitude and angle of the vector are given, the rectangular components are calculated as follows:
[tex]v_x=v\cos\theta[/tex]
[tex]v_y=v\sin\theta[/tex]
Where v is the magnitude of the vector and θ is the angle with respect to the x positive direction.
We are given the magnitude of the velocity (the speed) at which a plane is moving as v=100 mi/h at an angle of θ=25°, the vertical component of the velocity is:
[tex]v_y=100\sin 25^\circ[/tex]
Calculating:
[tex]v_y=42.26\approx 42[/tex]
The vertical speed in mi/h is 42.
How do bones develop and grow?
Answer:
Explanation:
Bones grow in length at the epiphyseal plate by a process that is similar to endochondral ossification. The cartilage in the region of the epiphyseal plate next to the epiphysis continues to grow by mitosis. The chondrocytes, in the region next to the diaphysis, age and degenerate.
A flat loop of wire consisting of a single turn of cross-sectional area 7.10 cm2 is perpendicular to a magnetic field that increases uniformly in magnitude from 0.500 T to 2.10 T in 1.07 s. What is the resulting induced current if the loop has a resistance of 1.60?
Answer:
The induced current is [tex]I = 0.00066 \ A[/tex]
Explanation:
From the question we are told that
The area is [tex]A = 7.10 \ cm^2 = 7.10 *10^{-4} \ m^2[/tex]
The initial magnetic field is [tex]B_i = 0.500 \ T[/tex]
The magnetic field after t =1.07 s is [tex]B_f = 2.10 \ T[/tex]
The resistance of the loop is [tex]R = 1.60 \ \Omega[/tex]
Generally the electromagnetic field induced is mathematically represented as
[tex]\epsilon = NA * \frac{B_f - B_i}{t}[/tex]
Where N is the number of turns which is 1 in the case of this question since there is only one loop
So
[tex]\epsilon = 1 * 7.10*10^{-4}* \frac{2.10 - 0.500}{1.07 }[/tex]
=> [tex]\epsilon = 0.00106 \ V[/tex]
Generally the value of the current is mathematically represented as
[tex]I = \frac{\epsilon}{R}[/tex]
[tex]I = \frac{0.00106}{1.60}[/tex]
[tex]I = 0.00066 \ A[/tex]
What unbalanced force is needed to give a 976 kg vehicle an acceleration of 2.50 m/s2? ASAP
Answer:
2440 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 976 × 2.5
We have the final answer as
2440 NHope this helps you
When an aluminum bar is connected between a hot reservoir at 720 K and a cold reservoir at 358 K, 3.00 kJ of energy is transferred by heat from the hot reservoir to the cold reservoir. (a) In this irreversible process, calculate the change in entropy of the hot reservoir._______ J/K
(b) In this irreversible process, calculate the change in entropy of the cold reservoir.
_______ J/K
(c) In this irreversible process, calculate the change in entropy of the Universe, neglecting any change in entropy of the aluminum rod.
_______ J/K
(d) Mathematically, why did the result for the Universe in part (c) have to be positive?
Answer:
a. -4.166 J/K
b. 8.37 J/K
c. 4.21 J/K
d. entropy always increases.
Explanation:
Given :
Temperature at hot reservoir , [tex]$T_h$[/tex] = 720 K
Temperature at cold reservoir , [tex]$T_c$[/tex] = 358 K
Transfer of heat, dQ = 3.00 kJ = 3000 J
(a). In the hot reservoir, the change of entropy is given by:
[tex]$dS_h= -\frac{dQ}{t_h}$[/tex] (the negative sign shows the loss of heat)
[tex]$dS_h= -\frac{3000}{720}$[/tex]
= -4.166 J/K
(b) In the cold reservoir, the change of entropy is given by:
[tex]$dS_c= \frac{dQ}{t_c}$[/tex]
[tex]$dS_c= \frac{3000}{358}$[/tex]
= 8.37 J/K
(c). The entropy change in the universe is given by:
[tex]$dS=dS_h+dS_c$[/tex]
= -4.16+8.37
= 4.21 J/K
(d). According to the concept of entropy, the entropy of the universe is always increasing and never decreasing for an irreversible process. If the entropy of universe decreases, it violates the laws of thermodynamics. Hence, in part (c), the result have to be positive.
A displacement vector with a magnitude of 20. meters could have perpendicular components with magnitudes of A. 10. m and 10. m B. 12 m and 8.0 m 12 m and 16 m D. 16 m and 8.0 m
Answer:10.m and 10. M
Explanation:
A displacement vector with a magnitude of 20. m could have perpendicular components with magnitudes of C. 12 m and 16 m.
A displacement vector with a magnitude of 20. meters can be decomposed in 2 perpendicular components.
They would form a right triangle, in which the displacement vector would be the hypotenuse (a) and the components would be the legs (b, c).
Given the magnitude of the legs, we can calculate the magnitude of the hypotenuse using the Pythagorean theorem.
[tex]c = \sqrt{a^{2} + b^{2} }[/tex]
Let's use this formula to calculate the displacement vector for each pair of legs.
A. 10. m and 10. m[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(10.m)^{2} + (10.m)^{2} }= 14.1m[/tex]
B. 12 m and 8.0 m[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(12m)^{2} + (8.0m)^{2} }= 14.4m[/tex]
C. 12 m and 16 m[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(12m)^{2} + (16m)^{2} }= 20m[/tex]
D. 16 m and 8.0 m[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(16m)^{2} + (8.0m)^{2} }= 17.9m[/tex]
A displacement vector with a magnitude of 20. m could have perpendicular components with magnitudes of C. 12 m and 16 m.
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An unbalanced 16.0N force is applied to a2.0kg mass. What is the acceleration of the mass?
Answer:
Yuh
Explanation:
What is the approximate horizontal velocity at which the boy in the diagram
threw the ball?
a. +5m/s
b. +20m/s
c. +25m/s
d. +30m/s
Answer:
D
Explanation:
5+25=30
Determine the force of gravitational attraction between a 92 kg student and a 550 g slice of pizza that are 25 cm apart
Answer:
F = 5.4 x 10⁻⁸ N
Explanation:
The gravitational force of attraction between two objects is given by Newton's Gravitational Law as follows:
F = Gm₁m₂/r²
where,
F = Gravitational Force = ?
G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²
m₁ = mass of student = 92 kg
m₂ = mass of pizza slice = 550 g = 0.55 kg
r = distance between student and pizza slice = 25 cm = 0.25 m
Therefore,
F = (6.67 x 10⁻¹¹ N.m²/kg²)(92 kg)(0.55 kg)/(0.25 m)²
F = 5.4 x 10⁻⁸ N
please help i will mark brainliest
what does a speedometer measure?
a. accerlation
b. velocity
c. speed
d. average speed.
Answer:
c. speed
Explanation:
Speedometer is a device used to measure the speed of a vehicle. I am pretty sure this is the correct option.
You discover a binary star system in which one member is a15MSun main-sequence star and the other star is a 10MSun giant. How do we believe that a star system such as this might have come to exist?
Answer:
Explanation:
The giant star must have at least once been the more massive star and then subsequently transferred some of its mass to its companion, the other star.
The two stars would be around the same age, so the more massive one would have turned into a giant first before the other one did or even had a chance to
A wire of radius 0.8 cm carries a current of 106 A that is uniformly distributed over its cross-sectional area. Find the magnetic field B at a distance of 0.07 cm from the center of the wire.
Answer:
The magnetic field is [tex]B = 2.319 *10^{-3} \ T[/tex]
Explanation:
From the question we are told that
The radius of the wire is [tex]r = 0.8 \ cm = 0.008 \ m[/tex]
The current is [tex]I = 106 \ A[/tex]
The position considered is d = 0.07 cm = 0.0007 m
Generally the magnetic field is mathematically represented as
[tex]B = \frac{\mu_o * I}{2\pi * \frac{r^2}{d} }[/tex]
Here [tex]\mu_o[/tex] is the permeability of free space with value [tex] 4\pi * 10^{-7} N/A^2[/tex]
So
[tex]B = \frac{ 4\pi * 10^{-7} * 106 }{2 * 3.142 * \frac{0.008^2}{0.0007} }[/tex]
=> [tex]B = 2.319 *10^{-3} \ T[/tex]
The spring constant, k, for a 22cm spring is 50N/m. A force is used to stretch the spring and when it is measured again it is 32cm long. Work out the size of this force
Answer:
5N
Explanation:
Given parameters:
Original length = 22cm
Spring constant, K = 50N/m
New length = 32cm
Unknown
Force applied = ?
Solution:
The force applied on a spring can be derived using the expression below;
Force = KE
k is the spring constant
E is the extension
extension = new length - original length
extension = 32cm - 22cm = 10cm
convert the extension from cm to m;
100cm = 1m;
10cm will give 0.1m
So;
Force = 50N/m x 0.1m = 5N
An experiment consists of throwing balls straight up with varying initial velocities. Which quantity will have the same value in all trials?a) initial momentum.
b) maximum height.
c) time of travel.
d) acceleration.
Answer:
the correct answer is D, acceleration of gravity
Explanation:
In a projectile launch problem it is described by the expressions
v = v₀ - g t
v² = v₀² - 2 g y
y = v₀ t - ½ g t²
By examining these equations we can see that acceleration is the magnitude that appears constant in all expressions.
This acceleration is the acceleration of gravity with a value of g = 9.8 m/s² and directed towards the center of the Earth
therefore the correct answer is D
What is the mass of a toy truck if 18 N of force is needed to accelerate the boat to
2 m/s2 ?
Answer:
9 kg
Explanation:
Force= Mass * Acceleration
18 N= Mass * 2 m/s^2
(18 N / 2 m/s^2) = Mass
Mass= 9 kg
The volume of water in a measuring cyclinder is 50 ml .When a piece of stone is immeresed in the cyclinder the volume of water increases to 87.3ml. Calculate volume of stone.
Answer:
37.3ml
Explanation:
87.3 ml-50 ml=37.3ml
Answer:
ok
Explanation:
g
Two manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?
Answer:
why do you think the senate changed the way it voted? What methods did the suf
why do you think the senate changed the way it voted? What methods did the suffragis
why do you think the senate changed the way it voted? What methods did the suffragists use to influence this change?
Two manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?
hi
lolTwo manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?ts use to influence this change?
Two manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?
hi
lolfragists use to influence this change?
Explanation:
Two manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?
hilol
1. When asteroids collided some of the broken materials fall into Earth's orbit. What do
astronomers call the debris when it hits planet Earth?
Answer:
meteoroids
Explanation:
when an asteroid (or really anything else) falls to earth, it is called a meteoroid
WHAT IS TRANS ATLANTIC SLAVE TRADE
At
room temperature, chlorine is a gas, bromine is a liquid, and
iodine is a solid. However, all
three elements share some
physical properties. They also
have very similar chemical
properties. They are grouped in the same column on the periodic table. What common property do
you observe?
Explanation:
One common property with all halogens in group 7 is that they are all non-metals.
Fluorine, chlorine, Bromine and Iodine are classified as non-metallic elements and they have a high electronegativity.
In chemical reactions, they are very reactive because they require just one electron to complete their octet configuration and be isoelectronic with noble gases.The most prominent observation from halogens is that they all non-metallic in nature.
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Question
An airplane flies eastward and always accelerates at a constant rate. At one position along its path, it has a velocity of
32.7 m/s. It then flies a further distance of 44500 m, and afterwards, its velocity is 50.3 m/s. Find the
airplane's acceleration
acceleration:
.016m/s2
Calculate how much time clapses while the airplane covers those 44500 m
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49 ENG
1:45 PM
9/17/2020
Answer:
Explanation:
initial velocity u = 32.7 m /s
final velocity v = 50.3 m /s
displacement s = 44500 m
acceleration a = ?
v² = u² + 2 a s
50.3² = 32.7² + 2 x a x 44500
2530.09 = 1069.29 + 89000a
a .016 m /s²
time taken t = ?
v = u + at
50.3 = 32.7 + .016 t
t = 1100 s
A runaway train car that has a mass of 15,000 kg travels at a speed of 5.4 m/s down a track. Compute the time required for a force of 1500 N to bring it to rest.
(a) 0.019 s
(b) 54s
(c) 4.2Ã106s
(d) 2.4Ã10â7s
Answer:
54 s
Explanation:
Given that,
Mass of a car, m = 15000 kg
Initial speed, u = 5.4 m/s
Final speed, v = 0 (it comes to rest)
Force, F = 1500 N
We need to find time when it comes to rest. Let it is t. Net force is given by :
F = ma, a is acceleration of the car
[tex]F=\dfrac{m(v-u)}{t}\\\\t=\dfrac{m(v-u)}{F}\\\\t=\dfrac{15000\times (0-5.4)}{1500}\\\\t=54\ s[/tex]
So, it will take 54 seconds to come to rest.
The time required to bring the car to rest is 54 s and the right option is (b) 54 s.
To calculate the time required for the force to bring the car to rest, we use the formula below.
Formula:
F = m(v-u)/t............ Equation 1Where:
F = Force applied to the carm = mass of the carv = final velocity of the caru = initial velocity of the cart = time.Make t the subject of the equation
t = m(v-u)/F............. Equation 2From the question,
Given:
F = -1500 N (stopping force)m = 15000 kgv = 0 m/s (to rest)u = 5.4 m/sSubstitute these values into equation 2
t = [1500(0-5.4)]/-1500t = -81000/-1500t = 54 secondst ≈ 54 sHence, The time required to bring the car to rest is 54 s and the right option is (b) 54 s.
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