Answer:
The rate of change of distance between the two ships is 18.63 km/h
Explanation:
Given;
distance between the two ships, d = 140 km
speed of ship A = 30 km/h
speed of ship B = 25 km/h
between noon (12 pm) to 4 pm = 4 hours
The displacement of ship A at 4pm = 140 km - (30 km/h x 4h) =
140 km - 120 km = 20 km
(the subtraction is because A is moving away from the initial position and the distance between the two ships is decreasing)
The displacement of ship B at 4pm = 25 km/h x 4h = 100 km
Using Pythagoras theorem, the resultant displacement of the two ships at 4pm is calculated as;
r² = a² + b²
r² = 20² + 100²
r = √10,400
r = 101.98 km
The rate of change of this distance is calculated as;
r² = a² + b²
r = 101.98 km, a = 20 km, b = 100 km
[tex]2r(\frac{dr}{dt} ) = 2a(\frac{da}{dt} ) + 2b(\frac{db}{dt} )\\\\r(\frac{dr}{dt} ) = a(\frac{da}{dt} ) + b(\frac{db}{dt} )\\\\101.98(\frac{dr}{dt} ) = 20(-30 ) + 100(25 )\\\\101.98(\frac{dr}{dt} ) = -600 + 2,500\\\\101.98(\frac{dr}{dt} ) = 1900\\\\\frac{dr}{dt} = \frac{1900}{101.98} = 18.63 \ km/h[/tex]
Jesse drives 120km to a farm. His trip takes 2 1/2 hoursWhat is his speed?
Speed = distance / time
Speed = 120 km / 2 1/2 hours
Speed = 48 km per hour
After You Read
Mini Glossary
atomic number: the number of protons in an atom of
an element
mass number: the sum of the number of protons and
neutrons in an atom
average atomic mass: the average mass of the element's
isotopes, weighted according to the abundance of each isotope
nuclear decay: a process that occurs when an unstable atomic
nucleus changes into another more stable nucleus by
emitting radiation
ion: an atom that is no longer neutral because it has gained or
lost electrons
radioactive: spontaneously emits radiation
isotope: an atom of the same element that has a different
number of neutrons
1. Review the terms and their definitions in the Mini Glossary. Write a sentence that
explains how to determine the number of neutrons in an isotope that has 6 protons and
a mass number of 13.
Answer:
protons+neutrons= mass number, so if the mass number is 13 and protons are 6 its 13-6=7 neutrons
Explanation:
mass number: the sum of the number of protons and
neutrons in an atom
this is key as it explains that protons+neutrons= mass number, so if the mass number is 13 and protons are 6 its 13-6=7 neutrons
Temperature is a measure of the...
a. Total energy in a substance
b. Average kinetic energy of molecules in a substance
c. Total kinetic energy in a substance
Answer:
Temperature is a measure of the average kinetic energy of the particles in an object. So, the answer will be B.
On the way home from school, Mr. X drives the first 10 miles at 55 mi/hr, the next 20 miles at 70 mi/hr, and the last 5 miles at 35 mi/hr. How far does Mr. X live from school?
Given :
On the way home from school, Mr. X drives the first 10 miles at 55 mi/hr, the next 20 miles at 70 mi/hr, and the last 5 miles at 35 mi/hr.
To Find :
How far does Mr. X live from school.
Solution :
To find the distance between Mr. X residence from school is simply given by summing all the distance he travelled .
So, distance = 10 + 20 + 5 miles
distance = 35 miles.
Hence, this is the required solution.
Please helppppppp!!!!!!!!!!!!!!
Answer:
circuit breaker
Explanation:
A circuit breaker is a device used for electrical safety. It consists of a switch designed to protect an electrical circuit from damage that may result from heating due to overload in the circuit.
Its basic function is to interrupt current flow through its switch that consists of metal stripe which bends when it gets hot.
Fuse has similar action with circuit breaker, the only difference is that fuse can only be used once because it melts when it gets hot.
Therefore, the correct answer is "circuit breaker"
A mass m, which is connected to a spring of spring constant k, is released from x = A to perform
a simple harmonic motion. Another mass 2m, which is connected to another spring of the same
spring constant k, is also released from x = A to perform a simple harmonic motion. Compare the
values of total mechanical energy stored in these two spring-mass systems.
Select the statement that is true:
A. Food chains and food webs have nothing to do with each other.
B. A food web and a food chain are different names for the same thing.
C. A food chain is a part of a food web.
D. A food web is part of a food chain.
Answer:
C
Explanation:
A food chain outlines who eats whom. A food web is all of the food chains in an ecosystem.
Answer:
C
Hope this helped :D
An astronaut hits a golf ball of mass m on the Moon, where there is no atmosphere and the acceleration due to gravity is g 6 , where g is the acceleration due to gravity on Earth. Assume that the golf club is in contact with the ball for a time t. Just after losing contact with the club, the ball has an initial speed v directed at an angle T above the horizontal. 6. What is the magnitude of the average force exerted by the club on the ball during contact
Answer:
The magnitude of the average force exerted by the club on the ball during contact = mv/t
Explanation:
Impulse exerted on the ball = Momentum of the ball = mass * velocity = m*v
As we know,
m*v = Integration of F.dt with limits 0 to T
Ft = mv
F = mv/t
The magnitude of the average force exerted by the club on the ball during contact = mv/t
Please helppppppp!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
I think the Bulb No. 2 will stop emitting light if the bulb No. 1 burns out.
What is the momentum of a lab cart with a mass of 0.60 [kg] and a speed of 2.2 [m/s]?
-3.67 [kg m/s)
-0.27 [kg m/s]
-1.32 [kg m/s)
-0.82 [kg m/s)
Answer:
1.32kgm/s
Explanation:
use the formula: p=mv
The momentum of a lab cart = -1.32 kg m/s
What is momentum?It is measure of the inertia of a body/ object .It can be calculated by multiplying mass with velocity .
General formula for momentum = M = m * v
given
mass = 0.60 kg
speed = 2.2 m/s
velocity = - 2.2 m/s ( answer is in negative , since mass is a scaler quantity but velocity is a vector quantity hence , velocity can be negative )
momentum = mass * velocity
= 0.60 * (-2.2 ) = -1.32 kg m/s
The momentum of a lab cart =c) -1.32 kg m/s
learn more about momentum
https://brainly.com/question/24030570?referrer=searchResults
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Two people that have identical weight are holding onto a massless pole while standing on horizontal frictionless ice. 1)If the guy on the left starts to pull on the pole, where do they meet
Answer:
Explanation:
From the missing image attached below, it is obvious that there no external force. This implies that they cannot change their position by merely just pulling the ropes. As a result, there will be no movement and no net force will exist.
So, if there is no external force;
The center of mass of the two people is:
[tex]X_{cm}= \dfrac{m_1x_1+m_2x_2}{m_1+m_2} \\ \\ X_{cm}= \dfrac{m(-3m)+m(+3m)} {m+m}\\ \\ X_{cm}= \dfrac{0}{2m} \\ \\ X_{cm} =0[/tex]
Thus, In the system, no movement occurs and all forces remain the same.
What is the period of revolution of a satellite with mass m that orbits the earth in a circular path of radius 7880 km (about 1500 km above the surface of the earth)
Answer:
Explanation:
For time period of revolution , the expression is as follows .
T² = 4π² R³ /GM , M is mass of the earth.
Putting the values
T² = 4π² (7880 x 10³)³ /(6.67 x 10⁻¹¹ )( 5.97 x 10²⁴ )
T² = 4.846 x 10⁷ s
T = 6.961 x 10³ s
= 6961 s
= 116 minutes .
Air in a thundercloud expands as it rises. If its initial temperature is 292 K and no energy is lost by thermal conduction on expansion, what is its temperature when the initial volume has tripled
Answer:
Explanation:
It is a case of adiabatic expansion .
[tex]T_1V_1^{\gamma-1}=T_2V_2^{\gamma-1}[/tex]
T₁ , T₂ are initial and final temperature , V₁ and V₂ are initial and final volume.
Given ,
V₂ = 3 V₁ and T₁ = 292 . γ for air is 1.4 .
[tex]( 3 )^{\gamma-1}= \frac{292}{ T_2}[/tex]
[tex]( 3 )^{1.4-1}= \frac{292}{ T_2}[/tex]
1.552 = 292 / T₂
T₂ = 188 K .
Objects 1 and 2 attract each other with a electrostatic force
of 72.0 units. If the distance separating Objects 1 and 2 is
tripled, then the new electrostatic force will be _units.
Answer:
8 units
Explanation:
From the question given above, the following data were obtained:
Initial force (F₁) = 72 units
Initial distance apart (r₁) = r
Final distance apart (r₂) = tripled = 3r
Final force (F₂) =.?
The final force between the two objects can be obtained by using the following formula:
F₁r₁² = F₂r₂²
72 × r² = F₂ × (3r)²
72r² = F₂ × 9r²
Divide both side by 9r²
F₂ = 72r² / 9r²
F₂ = 8 units
Therefore, the final force between the two objects is 8 units
Ferdinand the frog is hopping from lily pad to lily pad in search of a good fly
for lunch. If the lily pads are spaced 2.4 m apart, and Ferdinand jumps with a
speed of 5.4m/s, taking 0.60 s to go from lily pad to lily pad, at what angle
must Ferdinand make each of his jumps?
Answer:
θ = 33°
Explanation:
Here, we can use the formula for the total time of flight of a projectile to calculate the launch angle of frog:
[tex]T = \frac{2\ u\ Sin\theta}{g} \\\\Sin\theta = \frac{Tg}{2u}[/tex]
where,
θ = launch angle = ?
T = Total time of flight = 0.6 s
g = acceleration due to gravity = 9.81 m/s²
u = launch speed = 5.4 m/s
Therefore,
[tex]Sin\theta = \frac{(0.6\ s)(9.81\ m/s^2)}{(2)(5.4\ m/s)}\\\\\theta = Sin^{-1}(0.545)[/tex]
θ = 33°
Once a disk forms around a star, the process of planetary formation can begin. Rank the evolutionary stages for the formation of planets from earliest to latest.
a. Small clumps of matter stick together via the process of accrection to form plantesimals a few hundred kilometers in diameter
b. Dust keeps matter inside the disk cool long enough for planet formation to start
c. Planetisimals begin to accrete, forming protoplanets
d. Dust grains form condensation nuclei on which surrounding atoms condense to form small clumps of matter
e. A collection of a few planet-sized protoplanets remain in a fairly cleared out disk around the star
Answer: See explanation
Explanation:
The evolutionary stages for the formation of planets from earliest to latest will be:
1. Dust keeps matter inside the disk cool enough for planet formation to start
2. Dust grains form condensation nuclei on which surrounding atoms condense to form small clumps of matter.
3. Small clumps of matter stick together via the process of accretion to form planetesimals a few hundred kilometers in diameter.
4. Planetesimals begin to accrete, forming protoplanets.
5. A collection of a few planet-sized protoplanets remain in a fairly cleared out disk around the star
Engineers are working on a design for a cylindrical space habitation with a diameter of 7.50 km and length of 29.0 km. The habitation will simulate gravity by rotating along its axis. With what speed (in rad/s) should the habitation rotate so that the acceleration on its inner curved walls equals 8 times Earth's gravity
Answer:
The speed will be "0.144 rad/s".
Explanation:
Given that,
Diameter,
d = 7.50 km
Radius,
R = [tex]\frac{7.5}{2} \ Km[/tex]
Acceleration on inner curve,
= 8 times
Now,
As we know,
⇒ [tex]\omega^2R=8g[/tex]
or,
⇒ [tex]\omega=\sqrt{\frac{8g}{R} }[/tex]
On substituting the values, we get
⇒ [tex]=\sqrt{\frac{8\times 9.8}{\frac{7.5}{2}\times 10^3 } }[/tex]
⇒ [tex]=\sqrt{\frac{78.4}{3750} }[/tex]
⇒ [tex]=\sqrt{0.0209}[/tex]
⇒ [tex]=0.144 \ rad/s[/tex]
Parallel rays from a distant object are traveling in air and then are incident on the concave end of a glass rod with a radius of curvature of 15.0 cm. The refractive index of the glass is 1.50. What is the distance between the vertex of the glass surface and the image formed by the refraction at the concave surface of the rod? Is the image in the air or in the glass?
Answer:
the distance of image from the vertex is 45 cm and the image formed is in the glass.
Explanation:
distance of object, u = - infinity
radius of curvature, R = - 15 cm
refractive index, n = 1.5
Let the distance of image is v.
Use the formula
[tex]-\frac{n1}{u}+\frac{n2}{v}=\frac{n2- n1}{R}\\\\-\frac{1}{\infty }+\frac{1.5}{v}=\frac{1.5-1}{-15}\\\\v=45 cm[/tex]
The image is in the glass.
Instead of changing the the frequency you can change the tension to produce the next higher harmonic. What percentage of the tension would produce the next higher harmonic?
Answer:
[tex]\frac{T}{T_o} = ( 1 + \frac{1}{n} )^2[/tex]
Explanation:
This is a string resonance exercise, the wavelengths in a string held at the ends is
λ = 2L₀ / n
where n is an integer
the speed of the wave is
v = λ f
f = v /λ
the speed of the wave is given by the characteristics of the medium (string)
v = [tex]\sqrt{\frac{T}{\mu } }[/tex]
we substitute
f = [tex]\frac{n}{2L_o} \ \sqrt{\frac{T}{\mu } }[/tex]
to obtain the following harmonic we change n → n + 1
f’ = [tex]\frac{n+1}{2L_o} \ \sqrt{\frac{T_o}{\mu } }[/tex]
In this case, it tells us to change the tension to obtain the same frequency.
f ’= \frac{n}{2L_o} \ \sqrt{\frac{T}{\mu } }
how the two frequencies are equal
[tex]\frac{n+1}{2L_o} \sqrt{\frac{T_o}{ \mu } } = \frac{n}{2L_o} \sqrt{\frac{T}{\mu } }[/tex]
(n + 1) [tex]\sqrt{T_o}[/tex] = n [tex]\sqrt{T}[/tex]
[tex]\frac{T}{T_o} = ( \frac{n+1}{n} )^2[/tex]
[tex]\frac{T}{T_o} = ( 1 + \frac{1}{n} )^2[/tex]
this is the relationship of the voltages to obtain the following harmonic,
If an EM wave has a wavelength of 595 nm, what is its frequency?
5.02 x 10^5 s
1.99 x 10^-6 Hz
5.02 x 10^14 Hz
1.99 x 10^-15 s
None of the above
Explanation:
1.9If an EM wave has a wavelength of 595 nm, what is its frequency9 x 10^-6 Hz
Explanation:
aah cmmon just come over to my meet
A metallic circular plate with radius r is fixed to a tabletop. An identical circular plate supported from above by a cable is fixed in place a distance d above the first plate. Assume that d is much smaller than r. The two plates are attached by wires to a battery that supplies voltage V.
Required:
a. What is the tension in the cable?
b. Compute the energy stored in the electric field after the top plate was raised.
Answer:
A) F = V²E_o•πr²/2d²
B) U = E_o•Aπr²V²/2d
Explanation:
A) Since we have two circular plates, the formula for the electric field is expressed as;
E = V/d
Where;
V is voltage
d is distance
However, the net electric field produced is given by;
E' = V/2d
The tension in the cable can then be expressed as;
F = qE'
Where q is charge
Thus;
F = qV/2d - - - (eq 1)
We also know that;
C = q/V = E_o•A/d
A is area = πr²
Thus;
q/V = E_o•πr²/d
q = VE_o•πr²/d
Let's put VE_o•πr²/d for q in eq 1 to get;
F = V²E_o•πr²/2d²
B) formula for the energy stored in the electric field is;
U = ½CV²
From earlier, we saw that; C = E_o•A/d
Thus;
U = ½E_o•AV²/d
A = πr²
Thus;
U = E_o•Aπr²V²/2d
DUE IN 1 MINUTE PLS ANSWER QUICK ...A sound wave moving with a speed of 1500 m/s is sent from a submarine to the ocean floor. It reflects off the
ocean floor and is received 15s later. What is the distance between the submarine and the ocean floor?
Answer:
s = 11250 m = 11.25 km
Explanation:
The distance covered by the sound wave while traveling from submarine to ocean floor and then back to submarine can be given as follows:
[tex]s = vt[/tex]
but, the distance between the floor and the submarine will be half of this value:
[tex]s = \frac{1}{2}vt[/tex]
where,
s = distance between submarine and ocean floor = ?
v = velocity of sound = 1500 m/s
t = time taken for the round trip = 15 s
Therefore,
[tex]s = \frac{1}{2}(1500\ m/s)(15\ s)[/tex]
s = 11250 m = 11.25 km
a body thrown vertically upwards from grounf with inital vel 40m/s then time taken by it to reach max hieght is?
Answer:
t = 4.08 s
Explanation:
if the body is thrown upward, it has negative gravity. Knowing through the International System that the earth's gravity is 9.8 m/s²
Data:
Vo = 40 m/sg = -9.8 m/s²t = ?Use formula:
[tex]\boxed{\bold{t=\frac{-(V_{0})}{g}}}[/tex]Replace and solve:
[tex]\boxed{\bold{t=\frac{-(40\frac{m}{s})}{-9.8\frac{m}{s^{2}}}}}[/tex][tex]\boxed{\boxed{\bold{t=4.08\ s}}}[/tex]Time taken by it to reach max height is 4.08 seconds.
Greetings.
Describe two 'beneficial' aspects from the last 10,000 years of humanity, as well as two 'dis-advantageous' aspects. Agriculture should be your guiding point here.
Answer:
Two beneficial aspects of the last 10,000 years of mankind have been the development of writing and the development of civilized communities.
Thus, writing has allowed the recording of the different historical events that have taken place during the development of humanity, setting precedents for subsequent generations, allowing documenting the progress that humanity has been achieving. On the other hand, the development of civilized communities around urban systems has allowed for greater economic and social development on the part of human groups, which through cooperation have been acquiring an increasingly higher quality of life.
On the other hand, two negative aspects of these years have been the world overpopulation and the pollution of the planet.
Thus, the amount of the world's population has been getting closer and closer to the limit of our planet's carrying capacity, which could lead humanity to a point where resources are definitely scarce, causing famines and various catastrophes. On the other hand, the pollution arising from the development of industrial societies has notably undermined the health of individuals and has damaged their standard of living, while causing irreparable damage to the natural environment.
How much energy must be added to a 1-kg piece of granite with a specific
heat of 600 J/(kg°C) to increase its temperature from 20° C to 100° C?
A. 48,000 J
B. 4,800 J
C. 1,200,000 J
D. 60,000 J
Answer: 48,000 J
Explanation: i just did it
A ballistic pendulum is a device for measuring the speed of a projectile. The projectile is launched horizontally and embeds in a stationary block on the end of a string. The block-projectile system swings upward after the collision, reaching a maximum height. Which of the following statements is correct about the collision between the projectile-block system?
a. Kinetic energy of the system is conserved.
b. Linear momentum of the system is conserved.
c. Linear momentum of the system is not conserved.
d. The total mechanical energy of the system is conserved
Physics part 2
These the other questions 14 - 17
Answer:
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4) The SI unit of time is second. why?
Answer:
Second, fundamental unit of time, now defined in terms of the radiation frequency at which atoms of the element cesium change from one state to another. The second was formerly defined as 1/86,400 of the mean solar day—i.e., the average period of rotation of the Earth on its axis relative to the Sun.
source britannica
Explanation:
When a light bulb is connected to a 4.5 V battery, a current of 0.16 A passes through the bulb filament. What is the resistance of the filament
Answer:
R = 28.125 ohms
Explanation:
Given that,
The voltage of a bulb, V = 4.5 V
Current, I = 0.16 A
We need to find the resistance of the filament. Using Ohm's law,
V = IR
Where
R is the resistance of the filament
So,
[tex]R=\dfrac{V}{I}\\\\R=\dfrac{4.5}{0.16}\\\\R=28.125\ \Omega[/tex]
So, the resistance of the filament is equal to 28.125 ohms.