Answer:
In this case the board is moving towards the observer so the board will receive the frequency as a moving observer
The board then emits the sound received and becomes a moving source according to the driver in the ambulance
f' = f (V + Vo) / V where V is the speed of sound and f' is the frequency received by the moving board
Now the board becomes a moving source and
f' = f (V / (V - Vs) and V is again the speed of sound
Combining these equations we get
f = (V + Vo) / (V - Vs) = 700 (350 + 4) / (350 - 4) = 716 / s
The driver would hear 16 beats / sec
Note: one can do these separately
f' = 700 * (350 + 4) / 350 = 708 frequency received for moving observer
f' = 708 * 350 / (350 - 4) = 716 / sec moving source stationary observer
Every 5 sec one would hear 5 * 16 = 80 beats
6. Jones covered a distance of 50 miles on his first trip. On a later trip he traveled 300 miles while going three times as fast. His new time compared with the old time was: (a) three times as much, (b) twice as much, (c) the same, (d) half as much, (e) a third as much
first trip= 50 miles.
second trip= 300 miles.
to find:his new time compared to the old time.
solution:Let speed of the 1st trip x miles / hr. and speed of the 2nd trip 3x / hr.
Speed = Distance/Time
So, times taken to covered a distance of 50 miles on his first trip = 50/x hr.
= 100/x hr
Therefore, his new time compared with the old time was twice as much.
answer= b) twice as much
A 2-column table with 3 rows. The first column titled metal has entries aluminum, iron, lead. The second column titled density (grams per cubic centimeter) has entries 2.64, 7.50, 11.34.
You have discovered a meteorite that seems to be metallic. Its mass is 370 g, and you calculate the volume to be 50 cm3. Based on the three values provided, which metal would most likely match the composition of the meteorite?
aluminum
iron
lead
none of these (density is less than 1.0)
Iron,
I really hope this helped you
Explanation:
Answer:
Its just Cork and wax
Explanation:
I just did it on edge trust me
How would you compare the direction of the motion of the reflected pulse with respect to the incident pulse
The direction of the motion of the reflected pulse is inverted to that of the incident pulse.
What is a Pulse?This is a physics term which refers to the single disturbance that moves through a transmission medium.
The reflected pulse is inverted so the direction is from right to left while that of the incident pulse is from left to right.
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Balance the nuclear equation by giving the mass number, atomic number, and element symbol for the missing species.
The complete equation for the nuclear reaction is 10/5 B + 4/2He ------> 13/7N + 1/on
What is a nuclear reaction?A nuclear reaction is one in which the nucleus of one isotope is changed into the nucleus of another isotope. In this process some particles may be released.
Looking at the reaction equation, we know that the complete equation for the nuclear reaction is 10/5 B + 4/2He ------> 13/7N + 1/on
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Liquid pools of methane are found on the surface of Titan, one of Saturn's moons. The temperature on the surface of Titan is -180°C. What is this value on the Fahrenheit scale?
Answer:
-292 degrees F
Explanation:
C = 5/9( F -32)
-180 = 5/9 (F-32)
F = -292 degrees
What are two pieces of evidence that support the big bang theory?.
In an experiment, two objects, object X and object Y, travel toward each other and collide. Data are collected about
each object before, during, and after the collision, as shown in the table. Which ofthe following pairs of data, when
used together to create two graphs, could verify the conservation of momentum? Select two answers.
A) Average force exerted on object X by object Y and time of collision, because these measurements can be used to determine the change in momentum of object X.
B) Average force excreted on object Y by object X and time it collision, because these measurements can be used to determine the change in momentum of object Y.
C) Mass of object X and velocity of object X before collision, because these measurements can be used to determine the initial momentum of object X.
D) Mass of object Y and velocity of object Y before collision, because these measurements can be used to determine the initial momentum of object X.
(a) Average force exerted on object X by object Y and time of collision, because these measurements can be used to determine the change in momentum of object X.
(b) Average force excreted on object Y by object X and time it collision, because these measurements can be used to determine the change in momentum of object Y.
What is conservation of linear momentum?The principle of conservation of linear momentum, states that in the absence of external force, the sum of initial momentum must be equal to sum of final momentum.
P = mv
where;
m is massv is velocityp is momentumF = mv/t
Ft = mv
J = Δmv
where;
J is impulse = FtΔmv is change in momentummass of object X and object Y are constant, and cannot be used create graphs.
Impulse (product of force and time) received by an object is equal to change in the momentum of the object.
Thus, the pairs of data that can be used together to create two graphs, to verify the conservation of momentum are;
(a) Average force exerted on object X by object Y and time of collision, because these measurements can be used to determine the change in momentum of object X.
(b) Average force excreted on object Y by object X and time it collision, because these measurements can be used to determine the change in momentum of object Y.
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I would really appreciate the help on this pass paper question.
Answer:
Heat lost thru doors & windows = (100 - 75 - 5) = 20
20% is the fraction of heat lost thru doors and windows
One wants to obtain the largest savings per unit of cost
roof:
200 / 600 = 1/3
150 / 1000 = .15
40 / 2300 = .017
The largest of these is 1/3 so the most benefit would be obtained by insulating the roof
Since heat loss thru the roof depends on heat loss thru the attic, this is the most cost effective in reducing heat loss
The more the difference in temperature between the ceiling and roof (attic) the more heat will be lost thru the roof, so insulating the roof will decrease the heat loss of the attic
The vertical distance covered by a body falling freely under gravity is directly proportional to the square of the time for which it falls. If a body covers 300m in the first 10 seconds of its free fall, find the distance covered by the body in the next 10 seconds.
Answer:
S = 1/2 a t^2 distance covered by falling body from speed = 0
300 = 1/2 a 10^2
a = 600 m / 100 s^2 = 6 m/s^2
v = a t = 6 m/s^2 s * 10 s = 60 m/s speed after 10 sec
S2 = v t + 1/2 a t^2
S2 = 60 m/s * 10 sec + 3 m/s^2 * 100 s^2
S2 = 600 m + 300 m = 900 m
If Frequency F, velocity v, and density D are considered fundamental units, the dimensional formula for momentum will be :
Let's see
Momentum be P
[tex]\\ \rm\Rrightarrow P=[Frequency]^a[velocity]^b[Density]^c[/tex]
[tex]\\ \rm\Rrightarrow [P]=[F]^a[v]^b[D]^c[/tex]
[tex]\\ \rm\Rrightarrow [M^1L^1T^{-1}]=[T^{-1}]^a[L^1T^{-1}]^b[M^1L^{-3}]^c[/tex]
[tex]\\ \rm\Rrightarrow MLT^{-1}=T^{-a}L^bT^{-b}M^cL^{-3c}[/tex]
[tex]\\ \rm\Rrightarrow MLT^{-1}=T^{-a-b}L^{b-3c}M^c[/tex]
On comaparing
c=1So
b-3c=1b-3=1b=1+3b=4and
-a-b=-1-a-4=-1-a=-1+4=3a=-3So the unit is
DV⁴/F³Answer:
(Frequency)⁻³(velocity)⁴Density
Explanation:
See attachments.
5 A train of mass 1.5 X 105 kg is travelling at 40 ms-' when the brakes are applied and it decelerates steadily. The train travels a distance of 250 m before coming to a halt. (a) Calculate the deceleration of the train. (b) Find the average braking force.
Answer:
a)3.2m/s^2
b) -480,000N
Explanation:
mass of train= 150,000kg
velocity of train=40m/s
acceleration is negative
v^2=u^2-2as
v=0m/s
u=40m/s
s=250m
0=1600-500a
500a=1600
deceleration of 3.2m/s^2
newton's second law
F=ma
F= (150,000× -3.2)
F= -480,000N
A child swings back and forth on a swingset 40 times in 50 seconds. Find their frequency.
Answer:
.8
Explanation:
40 times is 40 'cycles' in 50 seconds
40 / 50 = .8 Hz ( f= Hz is cycles per second)
An electon in a box absorbs light. The longest wavelength in the absorbtion spectrum is 700 nm . How long is the box
Answer:
8.01 (10^-10) m
Explanation:
use the Particle in a box equation
E = (n^2) (h^2) / (8 m (L^2))
and energy of a particle as its wavelength equation
h c / lamda = E
combine the equations to get
h c / lamda = (n^2) (h^2) / (8 m (L^2))
get L alone
L^2 = (2^2 - 1^2) h lamda / 8 m c
the longest wavelength is produced by a jump from the first excited state to the ground so
n = 2 to n = 1
so
L^2 = (n1^2 - n2^2) h lamda / (8 m c)
h = 6.6(10^-34) J*s
c = 3(10^8) m/s
m = 9(10^-31) kg
lamda = 700(10^-9) m
n1 =2
n2=1
Atoms with certain characteristics are radioactive. Which of those below will
always be radioactive?
A. all atoms with more neutrons than protons
B. all atoms with an atomic number under 83
C. all atoms with fewer neutrons than protons
D. all atoms with an atomic number over 83
Answer:
D. all atoms with an atomic number over 83
general effects of global warming
Answer:
Warmer temperatures over time are changing weather patterns and disrupting the usual balance of nature. This poses many risks to human beings and all other forms of life on Earth.Changes in temperature cause changes in rainfall. This results in more severe and frequent storms. They cause flooding and landslides, destroying homes and communities, and costing billions of dollars.Water is becoming scarcer in more regions. Droughts can stir destructive sand and dust storms that can move billions of tons of sand across continents. Deserts are expanding, reducing land for growing food. Many people now face the threat of not having enough water on a regular basis.After you chew and swallow, food enters your digestive system where it can be broken down.
A.
True
B.
False
Answer:
A
Explanation:
Technically, your mouth is part of the digestive system though so I am not sure how accurate this question is.
Which phase of the moon is shown?
full moon
first quarter
waning gibbous
waxing crescent
A 0.4 kg rock is dropped through a 6m height. Find its speed as it hits the ground. What is its speed at half way down?
Answer:
83.1557575 M/s
Explanation:
V²=u²+2as
v=[tex] \sqrt{u ^{2} { + 2as}^{ } } [/tex]
u is initial velocity =0
here a =g
[tex]v = \sqrt{2gs} [/tex]
v=
[tex] \sqrt{2 \times 9.8 \times 6} [/tex]
v= 83.1557575 M/s
hello people ~
If a unit positive charge is taken from one point to another over an equipotential surface, then
(a) work is done on the charge.
(b) work is done by the charge.
(c) work done is constant.
(d) no work is done.
Answer:
(d) no work is doneExplanation:
Since the potential at each point of an equipotential surface is the same, the potential does not change while we move a unit positive charge from one point to anotherTherefore work done in the process is zero or no work is doneAnswer:
No work done
Explanation:
When a unit positive charge us taken from one point to another over an equipotential surface then
As it's equipotential no Displacement will happenAs no Displacement hence dw=0
No work done
The zone in which the greatest total mass of co2 is absorbed from the atmosphere.
The top layer is the zone in which the greatest total mass of co2 is absorbed from the atmosphere.
What is exosphere?The exosphere is the uppermost layer of Earth's atmosphere, located between 700 and 10,000 kilometers above the surface and merging with the solar wind at its summit.
The exosphere is a narrow, ambience space that surrounds a planetary contains particles that are gravitational forces connected to that body yet have such a low density that they are effectively collisionless.
Hence, the top layer is the zone in which the greatest total mass of co2 is absorbed from the atmosphere.
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1. What could be the structure in the volcano that serves as a source of
geothermal energy?
A. Caldera
B. Magma chamber C. Summit D. Vent
Answer:
it is magma chamber
Explanation:
How would life on earth be different if its axis was not tilted with respect to its orbit?.
Answer:
oone side at a time would be hot and the other oone
Explanation:
One side will be hot and the other cold no in-between
What has 8 protons 10 neutrons and 10 electrons
The table shows the speed of ultrasound waves in different tissues in the human body.
Tissue
Speed
(m/s)
Air 330
Fat 1,450
Water 1,480
Liver 1,550
Kidney 1,560
Blood 1,570
Muscle 1,580
Bone 4,080
What happens to an ultrasound wave that moves from muscle to bone?
(1 point)
The frequency of the wave decreases.
The frequency of the wave increases.
The wavelength of the wave decreases.
The wavelength of the wave increases
Answer:
the frequency of the wave increases
Answer:
The wavelength of the wave increases
Explanation:
Just did the test
What is meant by the "objectivity" of web documents, and what are the three things to look for when evaluating a website for objectivity? (site 1)
Objectivity refers to the ability of a writer to present ideas or situations factually as they are without partiality.
What is objectivity in writing?Objectivity refers to the ability of a writer to present ideas or situations factually as they are and not based on his or her own preconceived notions or bias.
To check for objectivity in a web document, one has to ;
check the source of the material compare different web documents with itcheck on the websites credibility rating from othersTherefore, objectivity means being truthful and impartial.
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*Two objects have an elastic collision. Before the collision they approach one another with a velocity of 45 m/s. With what speed will they be separating after the collision?
In the elastic collision, the velocity of approach and velocity of separation is the same. The velocity of the separation after the collision will be 45 m/s.
What is collision?The abrupt, violent coming together in direct contact of two bodies is known as the collision. a falling object and a floor are examples of collisions.
When the distance between two ships decreases while the bearings remain constant, a collision occurs.
Objects have an elastic collision. Before the collision, they approach one another V1= V2=45 m/sec
The velocity of the approach is found as;
[tex]\rm = U_1-U_2 \\\\\ = 45-45 \\\\ = 0[/tex]
As we know,
[tex]\rm e = \frac{U_2-U_1}{V_2-V_1}[/tex]
The velocity of separation is found as;
[tex]\rm V_1-V_2[/tex]
and, e=1 for elastic collision.
[tex]\rm U_1-U_2=V_2-V_1[/tex]
[tex]\rm V_2-V_1 = 0 \\\ V_2 = V_1 = 45 \ m/sec[/tex]
In the elastic collision, the velocity of approach and velocity of separation is the same.
Hence the velocity of the separation after the collision will be 45 m/s.
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The more light bulbs you add to a series circuit, the _______ the lights will become.
A. Brighter
B. Dimmer
C. Hotter
D. None of the Above
Answer:
brighter
Explanation:
the more light bulbs you add to a series of circuits, the brighter the room will be.
Explain why we say that energy from the washing machine is wasted' as thermal energy?
Explanation:
In washing machine, the electrical energy is converted in kinetic energy then the mechanical energy is converted into thermal (heat) energy.
A child pushes, with a constant force, a merry-go-round with a radius of 2.5 m, from rest to an angular velocity o
f 3.0 rad/s in 8.0 s. What is the merry-go-round's tangential acceleration? What is the merry-go-rounds
centripetal acceleration? What is the merry-go-rounds angular acceleration?
The centripetal acceleration of the merry-go-round is 0.938 m/s² and the angular acceleration of the merry-go-round is 0.375 rad/s².
Angular velocity of the merry-go-roundThe angular acceleration of the merry-go-round is calculated as follows;
α = ω/t
α = 3/8
α = 0.375 rad/s²
Centripetal acceleration of the merry-go-roundThe centripetal acceleration of the merry-go-round is calculated as follows;
a = αR
a = 0.375 x 2.5
a = 0.938 m/s²
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The Hermes is a rotating space station that allows its occupants to experience simulated gravity. If its angular velocity is 0.66 rad/s and gives a simulated gravity of 0.4g, what is its diameter?
Answer:
a = v^2 / R = ω^2 R centripetal acceleration
.4 g = .4 * 9.80 m/s^2 = 3.92 m/s^2
R = a / ω^2 = 3.92 / .66^2 = 9.0 m
D = 2 R = 2 * 9.0 = 18.0 m diameter