Answer:
Jared has earned 23% of the $52 he needs to buy a new jacket. Find 23% of $52.
Which expression can you use to find 23% of 52?
✔ 0.23 × 52
23% of $52 is $
✔ 11.96
.
An easy way to check your answer is to use the friendly
✔ 25%
and divide 52 by
✔ 4
to get
✔ 13
.
Explanation:
You are driving down the road heading north at 15 m/s. An ambulance is driving in the opposite direction (south) towards you at 25 m/s. If the ambulance's siren emits sound at a frequency of 2 kHz, what frequency do you hear? Assume that the speed of sound is 340 m/s. a. 1780 Hz b. 1945 Hz c. 2254 Hz d. 2063 Hz e. 2000 Hz
Answer:
d. 2063 Hz
Explanation:
Given that the source of the sound (the ambulance) is heading towards the observer, we have;
fL= (v ± vL/v ± vS) fS
Where;
v = speed of sound = 340 m/s
vL = velocity of the listener = 15 m/s
vS = velocity of the source = 25 m/s
fS = frequency of source = 2 kHz
Since the source is moving towards the observer we subtract;
Substituting values;
fL = (340 - 15/340 - 25)2 *10^3
fL = 2063Hz
The frequency of the siren heard by the driver is approximately 2254Hz.
Hence, Option C) 2254Hz is the correct answer.
Given the data in the question;
Velocity of observer; [tex]v_o = 15m/s[/tex]Velocity of source; [tex]v_s = 25m/s[/tex]Actual frequency (source); [tex]f = 2kHz = 2000Hz[/tex]Velocity of sound; [tex]v = 340m/s[/tex]Frequency heard by observer; [tex]f' = \ ?[/tex]
To find the frequency heard by the observer, we Doppler Effect Equation:
[tex]f' = [ \frac{v+v_o}{v - v_s} ] f[/tex]
Where [tex]f'[/tex] is the observed frequency, [tex]f[/tex] is the actual frequency, [tex]v[/tex] is the velocity of sound, [tex]v_o[/tex] is the velocity of the observer and [tex]v_s[/tex] is the velocity of the source.
We substitute our given values into the equation
[tex]f' = [ \frac{340m/s\ +\ 15m/s}{340m/s\ -\ 25m/s} ] 2000Hz\\\\f' = [ \frac{355m/s}{315m/s} ] 2000Hz\\\\f' = 2253.968Hz\\\\f' = 2254Hz[/tex]
The frequency of the siren heard by the driver is approximately 2254Hz.
Hence, Option C) 2254Hz is the correct answer.
Learn more: https://brainly.com/question/1330077
At the equator, the earth spins a distance of 25,992 miles every day. What speed does the earth spin at in mph?
At the equator, the earth spins a distance of 25,992 miles every day, which is equal to 1083 mph.
What is equator?
An equator is a hypothetical line that circles the center of a planet or other celestial body. It is located at 0 degrees latitude, midway between the north and south poles. The globe is divided into northern and southern hemispheres by an equator.
The diameter of the Earth is also larger at the Equator, resulting in a phenomenon known as an equatorial bulge. A circle's diameter is measured by a straight line that goes through its center and has its ends on the circle's edge. The diameter of latitudes such as the Equator and the Arctic Circle can be calculated by scientists.
At the equator, the earth spins a distance of 25,992 miles every day
This is equal to (25992 ÷ 24) miles per hour
= 1083 mph.
Learn more about equator here:
https://brainly.com/question/24203207
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A vector B , with a magnitude of 8.0 m, is added to a vector A , which lies along an x axis. The sum of these two vectors is a third vector that lies along the y axis and has a magnitude that is twice the magnitude of A . What is the magnitude of A?
Answer:
the magnitude of A is 3.577
Explanation:
According to the question it is given that there is a magnitude of 8.0 m that added to the vector A that lies on x axis also the sum of two vectors would be third vector by considering the y axis and the magnitude is the twice of the magnitude B
The computation of the magnitude of A is shown below:
[tex]A \hat{i} + B = 2A \hat{j}\\\\A \hat{i} + 8 = 2A \hat{j}\\\\8 = 2A \hat{j} - A \hat{i}\\\\\mid8\mid = \sqrt{(2A \hat{j})^2 + (- A \hat{i})^2} \\\\8 = \sqrt{5A} \\\\A = \frac{8}{\sqrt{5} }[/tex]
A = 3.577
Hence, the magnitude of A is 3.577
Which of the following is an example of Newton’s second law of motion?
A.....Catie’s skateboard hits a curb and she falls forward onto the grass.
B.....a tissue and a rock are dropped from a ladder. The rock exerts a greater force when it hits the ground.
C.....a person stands on a chair and pushes down, and the chair pushes upwards on
the person.
D......Tires from a bike push against the road, and the road pushes back.
Answer:
B
Explanation:
Newton’s Second Law of Motion
Newton’s Second Law of Motion states that ‘when an object is acted on by an outside force, the mass of the object equals the strength of the force times the resulting acceleration’.
This can be demonstrated dropping a rock or and tissue at the same time from a ladder. They fall at an equal rate—their acceleration is constant due to the force of gravity acting on them.
The rock's impact will be a much greater force when it hits the ground, because of its greater mass. If you drop the two objects into a dish of water, you can see how different the force of impact for each object was, based on the splash made in the water by each one.
Answer:
b
Explanation:
A bat moving at 3.7 m/s is chasing a ying insect. The bat emits a 36 kHz chirp and receives back an echo at 36.79 kHz. At what speed is the bat gaining on its prey? Take the speed of sound in air to be 340 m/s.
Answer:
The speed the bat is gaining on its prey is 0.03m/s
Explanation:
Given;
speed of the bat, v₀ = 3.7 m/s
frequency of the bat, F₀ = 36 kHz
frequency of the source, Fs = 36.79
This is relative motion between a source of the sound and the observer. The phenomenon is known as Doppler effect.
Apply the following equation to determine the speed of the insect which is the source;
[tex]F_0 = F_s[\frac{v+v_0}{v-v_s} ]\\\\\frac{F_0}{F_s} = [\frac{v+v_0}{v-v_s} ]\\\\\frac{36.79}{36} = \frac{340+3.7}{340-v_s}\\\\1.0219 = \frac{343.7}{340-v_s}\\\\ 340-v_s = \frac{343.7}{1.0219}\\\\340-v_s = 336.33\\\\v_s = 340-336.33\\\\v_s = 3.67 \ m/s[/tex]
The speed the bat is gaining on its prey = 3.7m/s - 3.67m/s = 0.03 m/s
Therefore, the speed the bat is gaining on its prey is 0.03m/s
You used measurements of distance and time to find velocity. When you calculate the uncertainty on your measurements of time, what units will that uncertainty have?a. counts/time b. time^2 c. time d. time/counts
Answer:
C
Explanation:
The uncertainty will carry the unit of time because it's the time in itself that has error, and not the distance, nor the velocity.
Had it been the uncertainty was to the velocity, then we would say both the unit of the distance and that of the time would have been affected. But as it stands, only that of time will be affected.
A 72.0-kg person pushes on a small doorknob with a force of 5.00 N perpendicular to the surface of the door. The doorknob is located 0.800 m from axis of the frictionless hinges of the door. The door begins to rotate with an angular acceleration of 2.00 rad/s2, What is the moment of inertia of the door about the hinges? A) 2.74 kg m2 B) 1.88 kg m2 C) 0.684 kg m2 D) 4.28 kg m2 E) 7.52 kg m2
Answer:
[tex]I=2\ kgm^2[/tex]
Explanation:
Given that,
Mass of a person, m = 72 kg
Force acting on a doorknob, F = 5 N
The doorknob is located 0.800 m from axis of the frictionless hinges of the door.
The angular acceleration of the dor, a = 2 rad/s²
We need to find the moment of inertia of the door about the hinges.
The person applies a torque to the door and it is given by :
[tex]\tau=Fr[/tex] ...(1)
Also, the torque is equal to :
[tex]\tau=I\alpha[/tex] ...(2)
From equation (1) and (2) we get :
[tex]Fr=I\alpha[/tex]
I is the moment of inertia
[tex]I=\dfrac{Fr}{\alpha }\\\\I=\dfrac{5\times 0.8}{2}\\\\=2\ kgm^2[/tex]
So, the moment of inertia of the door about the hinges is [tex]2\ kgm^2[/tex].
Two flat glass surfaces are separated by a 150-nm gap of air.
A. What wavelength light illuminating the air gap is reflected brightly?
B. What wavelength of radiation is not reflected in the air gap?
Answer:
a. 600 nm
b. 300 nm
Explanation:
According to the question it is given that there is two flat glass surface that is separated by 150nm air gap
Based on the above information
The computation is shown below
a. The bright thickness is
[tex]t = \frac{\lambda}{2} (m - \frac{1}{2} )\\\\\lambda = \frac{2t}{(m - \frac{1}{2} )} \\\\\frac{2(150)}{(1 - \frac{1}{2} )} \\\\[/tex]
= 600 nm
b. The dark thickness is
[tex]t = \frac{m\lambda }{2} \\\\\lambda = \frac{2t}{m} \\\\\frac{2(150)}{1}[/tex]
= 300 nm
Find the mass of a water balloon that was thrown at Bookie with a force of 42 N and an acceleration of 3.99 m/s2.
Answer:
10.52 kgExplanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
[tex]m = \frac{f}{a} \\ [/tex]
f is the force
a is the acceleration
From the question we have
[tex]m = \frac{42}{3.99} \\ = 10.5263...[/tex]
We have the final answer as
10.52 kgHope this helps you
How is energy that is stored in food released?
A- atoms increase in movement
B- atoms are split
C- heat is released
D-chemical bonds in fats are proteins are broken
Answer:
i think its A
Explanation:
Answer:
D
Explanation:
The chemical energy stored in food is released by cells through the process of respiration. (cellular respiration)
This stored energy is released whenever these chemical bonds are broken in metabolic processes such as cellular respiration. Cellular respiration is the process by which the chemical energy of “food” molecules is released and partially captured in the form of ATP.
Degree day calculations are based on a temperature of?
Answer:
65F
Explanation:
Explain why balancing the forces acting on a body is not enough to establish equalibrium. Give anexample to justify your answer.
Answer:
Please find the answer in the explanation.
Explanation:
Balancing the forces acting on a body is not enough to establish equlibrium because of the principle of moment say that:
1.) For equilibrium to be attained, the sum of clockwise moment must be equal to the sum of anticlockwise moments.
2.) The sum of upward forces must be equal to the sum of the downward forces
According to the definition of moment, is the product of force and perpendicular distance.
Therefore, the perpendicular distance is needed to be considered.
White light (380nm-750 nm) strikes a diffraction grating (900 lines/mm) at normal incidence. What is the highest-order visible maximum that is formed?
Answer:
Highest order: m = 1
Explanation:
Formula for solving this is;
dsin θ_m = mλ
We want to find m, thus;
m = (dsin θ_m)/λ
We are told that White light spans from 380nm - 750 nm. Thus, at maximum, λ = 750 nm.
θ_m = 90°
d = (900 lines/mm) = 9000 × 10^(-7) lines/nm
Since we want to find m, the units nm has to cancel out in the equation.
Thus, we will write d in nm/lines as (10^(7))/9000 nm/lines
Thus;
m = ((10^(7))/9000 × sin 90)/750
m = 1.48
Approximately 1
Consider two balls on a horizontal, frictionless surface. Ball A (with mass ma) is moving toward ball B (with mass mb = 1 kg). Ball B is initially at rest.a. (5 pts) If their collision is perfectly elastic, what should be the mass of ball A such that it stops upon collision if ball A's initial velocity is +3.1416 m/s?b. (5 pts) Using conditions in question (a), what is the speed of ball B after collision? Is it moving in the initial direction of ball A or opposite it?c. (5 pts) Consider this 2nd scenario: If the collision is perfectly inelastic, what is the speed of the balls after collision? [Use the mass that you calculated from question (a) for ball A.]d. (5 pts) Now, consider a 3rd scenario: Ball A (with arbitrary speed va) collides with a stationary ball B (mass is mb = 1 kg). After collision, you observed that ball A and ball B are now moving at the same speed va but toward opposite directions: Ball A is heading opposite its original direction, while B is moving along the initial direction of A. What is the mass of ball A?
Answer:
Explanation:
When two ball of identical mass collides perfectly elastically , there is exchange of velocity between the two balls .
Here ball be was at rest initially . After collision ball A comes to rest , so there is complete exchange of velocity . Hence ball A must have same mass as that of B . mass of ball A = 1 kg .
b ) Due to complete exchange of velocity , velocity of ball A will be picked up by ball B . Hence velocity of ball B = 3.1416 m /s . Yes it will be moving in the direction of ball A .
c )
In case of perfectly inelastic collision they will become single mass
total mass = 2 kg
applying conservation of momentum law
their common velocity after collision = 1 x 3.1416 / 2 = 1.57 m /s
d )
Applying conservation of momentum law
initial momentum = Ma x va
they move in opposite direction after collision
their total momentum after collision
1 x va - Ma va
applying law of conservation of momentum
1 x va - Ma va = Ma va
va = 2Ma va
Ma = .5 kg .
A metallic laboratory spring is typically 5.50cm long and 0.140 cm in diameter and has 50.0 coils. If you connect such a spring in an electric circuit, how much self-inductance must you include for it if you model it as an ideal solenoid?
L = ________?
Answer:
um hm err
Explanation:
Something that has many particles in a small space would have a ————- density
Fill in blank
Answer:
a high density i believe
Explanation:
Answer:
it may have a higher density
The half-lives for the radioactive decay of various elements are listed below.
Parent Isotope
Daughter Isotope
Half Life (years)
Carbon-14
Nitrogen-14
5730
Uranium-235
Lead-207
710 million
Potassium-40
Argon-40
1.25 billion
a) Suppose you discovered a meteorite that contains a small amount of potassium-40 and its decay product argon-40. You determine that 1/8 of the original potassium-40 remains; the other 7/8 has decayed into argon-40. How old is the meteorite?
b) A piece of cloth was painted with organic dye 34380 years ago. What percentage of the original carbon-14 in the organic dye remains after all this time?
c) The oldest minerals found on Earth are zircons. One isotope used to measure their age is uranium-235. A single crystal contained 20 nanograms of uranium-235 when it first formed. How much uranium-235 does the crystal still contain if it formed 2.84 billion years ago?
Answer:
D ko alam pasensya ka na ha
a. An object weighs 7.84 N when it is in air and 6.86 N when it is immersed in water. What is the specific gravity of the object?
b. How much pressure does it take for a pump to supply a drinking fountainwith 300 kPa, if the fountain is 30.0 m above the pump?
Answer:
a
[tex]W_s = 8[/tex]
b
[tex]P = 594 000 \ Pa[/tex]
Explanation:
Considering question a
From the question we are told that
The weight of the object in air is [tex]W_1 = 7.84 \ N[/tex]
The weight of the object in water is [tex]W_2 = 6.86\ N[/tex]
Generally the specific gravity of the object is mathematically represented as
[tex]W_s = \frac{W_1 }{W_1 - W_2 }[/tex]
=> [tex]W_s = \frac{7.84}{7.84 -6.86 }[/tex]
=> [tex]W_s = 8[/tex]
Considering question b
From the question we are told that
The pressure required is [tex]P_r = 300 \ kPa = 300 *10^{3} \ Pa[/tex]
The height is [tex]h = 30.0 \ m[/tex]
Generally the pressure require to get the water to the given height is mathematically represented as
[tex]P_h = \rho * g * h[/tex]
Here [tex]\rho[/tex] is the density of water with value [tex]\rho = 1000 \ kg / m^3[/tex]
So
[tex]P_h = 1000 * 9.8 * 30[/tex]
=> [tex]P_h = 294000 \ Pa[/tex]
Generally the pressure require to pump the water to the given height at the require pressure is mathematically represented as
[tex]P = P_h + P_r[/tex]
=> [tex]P = 294000 + 300*10^{3}[/tex]
=> [tex]P = 594 000 \ Pa[/tex]
Which of the following is most likely to occur at a convergent boundary?
A: Mountain formation
B: Seafloor spreading
C: Faults
D: Mid-Atlantic rift
Answer:A: mountain formation
Explanation:
Find the Acceleration of a car with the mass of 1200kg and a force of 11x10^3 N
Answer:
9.17 m/s²Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
[tex]a = \frac{f}{m} \\ [/tex]
f is the force
m is the mass
From the question we have
[tex]a = \frac{11 \times {10}^{3} }{1200} \\ = 9.16666...[/tex]
We have the final answer as
9.17 m/s²Hope this helps you
When a student shines a 540 nm laser through this grating, how many bright spots could be seen on a screen behind the grating?
Complete Question
A commercial diffraction grating has 600 lines per mm.
When a student shines a 540 nm laser through this grating, how many bright spots could be seen on a screen behind the grating?
Answer:
The number of bright spots is [tex]m = 7[/tex]
Explanation:
From the question we are told that
The wavelength is [tex]\lambda = 540 nm = 540 *10^{-9} \ m[/tex]
The number of lines per length the commercial diffraction grating has is [tex]L = 600 \ lines / mm = 600 * 1000 \ lines / m = 600 *10^{3} \ lines / m[/tex]
Generally the condition for constructive interference is mathematically represented as
[tex]dsin(\theta) = n\lambda[/tex]
Here d is the separation between the gratings which is mathematically represented as
[tex]d=\frac{1}{L}[/tex]
=> [tex]d=\frac{1}{600 *10^{3}}[/tex]
=> [tex]d= 1.67 *10^{-6 } \ m[/tex]
and n is the order of bright fringe, the maximum number is seen when [tex]\theta = 90^o[/tex]
So
[tex]1.67 *10^{-6}sin(90) = n * 540 *10^{-9 }[/tex]
=> [tex]n = 3[/tex]
Generally the number of bright spot (considering central bright fringe and the same order of bright fringe on each side of the central bright fringe) is mathematically represented as
[tex]m = n * 2 + 1[/tex]
=> [tex]m = 3 * 2 + 1[/tex]
=> [tex]m = 7[/tex]
help please! what is the right answer
what tells you the strength of a wave?
Guys I really need help here
a) Find the energy needed
to to heat a tank holding water of 60 kg to rise the temperature from 10 degree Celsius to 60 degree Celsius (c=4200
J/K°C)
b)find the time for rising this much temperature if the power of heater is 3KW
Answer:
c
Explanation:
A child swings a sling with a rock of mass 1.3 kg, in a radius of 0.6. From rest to an angular velocity of 6 rad/s. What is the rotational kinetic energy of the rock?
Answer:
8.42Joules
Explanation:
The rotational kinetic energy, denoted by E(rotational), can be calculated using the formula:
E(rotational) = 1/2 × I × ω²
Where;
I = moment of inertia (kgm²)
ω = angular velocity (rad/s)
However, we need to calculate the moment of inertia in this question by using the formula:
I = m × r²
Where;
m = mass (1.3kg)
r = radius (0.6m)
I = 1.3 × 0.6²
I = 1.3 × 0.36
I = 0.468 kgm²
Since I = 0.468 kgm², ω = 6 rad/s, we can calculate rational kinetic energy using:
K.E(rotational) = 1/2 × I × ω²
K.E(rotational) = 1/2 × 0.468 × 6²
K.E(rotational) =1/2 × 0.468 × 36
K.E(rotational) = 18 × 0.468
K.E(rotational) = 8.424
K.E(rotational) = 8.42Joules
What is a physical combination of two or more substances that are blended together without forming a new substance?
Answer:
It is called a mixture.
Explanation:
A mixture is a physical combination of 2 or more substances that are blended together without forming a new substance.
Kenny eats a snickers bar. Her body uses the candy as energy to move her muscles. What type of energy conversion is this an example of?
A- Thermal to chemical
B- Chemical to mechanical
C-Chemical to thermal
D- Potential to mechanical
Answer:
c- chemical to thermal
Explanation:
Anuja is holding a stuffed dog, with a mass of 0.30 kg, when Derek decides that he wants it and tries to pull it away from Abuja. If Derek pulls horizontally on the dog with a force of 10.0 N and Anudja pulls with a horizontal force of 11.0 N, what is the horizontal acceleration of the dog?
Answer:
a = 3.33 m/s²
Explanation:
The horizontal acceleration of the dog can be found by using Newton's Second Law of Motion as follows:
F = ma
where,
F = Unbalanced force applied on the dog = 11 N - 10 N = 1 N
m = mass of the dog = 0.3 kg
a = horizontal acceleration of dog = ?
Therefore,
1 N = 0.3 kg(a)
a = 1 N/0.3 kg
a = 3.33 m/s²
An 4.0-kg fish pulled upward by a fisherman rises 1.9 m in 2.4 s, starting
from rest. Assuming the acceleration is constant, find the magnitude
and direction of the net force acting on the fish during this interval.
Answer:
2.64N
Explanation:
Force = mass * acceleration
Given
mass = 4kg
distance = 1.9m
Time t = 2.4s
Get the acceleration using the equation of motion
S = ut + 1/2at²
1.9 = 0 + 1/2a(2.4)²
1.9 = 5.76a/2
1.9 = 2.88a
a = 1.9/2.88
a = 0.66m/s²
Get the magnitude of the force
Force = 4 * 0.66
Force = 2.64N
Hence the net force acting on the fish is 2.64N
Cars have safety features to protect people during a crash. A bumper is one type of safety feature. Which bumper design do
you think is safer?
a bumper that crumples
a bumper that's rigid
Answer:
Explanation:
second one ??? pls i hope im right
Answer:
A bumper that crumbles (plato)
Explanation: