Answer:
The average speed for the entire run is 12 km/h.
Explanation:
The average speed is given by the following equation:
[tex] \overline{v} = \frac{d_{T}}{t_{T}} [/tex]
Where:
[tex]d_{T}[/tex]: is the total distance
[tex]t_{T}[/tex]: is the total time
If during the first hour, they ran a total of 13 kilometers and then, they ran 5.0 kilometers during the next half an hour we have:
[tex] d_{T} = 13 km + 5 km = 18 km [/tex]
[tex] t_{T} = 1 h + \frac{1}{2} h = 1.5 h [/tex]
Hence, the average speed is:
[tex] \overline{v} = \frac{d_{T}}{t_{T}} = \frac{18 km}{1.5 h} = 12 km/h [/tex]
Therefore, the average speed for the entire run is 12 km/h.
I hope it helps you!
When water turns to ice:
1. The distances between the molecules increase, 2. Heat is released into the environment, 3. The temperature of the ice does not change during the transformation, 4. All statements are correct.
Answer:
1
Explanation:
What is the mass in grams of 3.1 mol of mercury, Hg Show Your work
Answer:
621.83grams
Explanation:
Using the formula;
Mole = mass ÷ molar mass
Where;
Mole = mol
Mass = grams
Molar mass = g/mol
According to the information given in this question, number of moles = 3.1mol, mass of Hg = ?, Molar mass (MM) of Hg = 200.59g/lol
Hence, using mole = mass/MM
3.1 = mass / 200.59
mass = 200.59 × 3.1
Mass = 621.829
Mass = 621.83grams
Gases, just like liquids are made of particles which can be further classified as atoms or molecules,
True
False
Answer:
True
Explanation:
Solids, Liquids, and Gases are all make up of atoms and molecules.
A uniform electric field exists in a region of space containing no charges. What can you conclude about the net electric flux through a gaussian surface placed in this region of space?
The net electric flux in such gaussian surface is zero.
In a uniform electric field existing in a region of space and contains no charge, it is impossible for there to be an electric flux in such space. This is because flux generated in an electric field is a product of the charge and the permittivity of the free space.
In other words, every field line sent into a given closed surface continues through the interior and is typically directed outward somewhere on the surface if there is no provided net charge there. The net or total electric flux is zero because the negative flux barely equals the positive flux in magnitude.
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Using 6. 0×1024 kg for the mass of the earth, what is the acceleration of the earth toward her as she accelerates toward the earth with an acceleration of 9. 8 m/s2 ? assume that the net force on the earth is the force of gravity she exerts on it.
The value of the acceleration of the earth toward it when it accelerates toward the earth with 9.8m/s² is a = 7.35×10-²³m/s².
What are forces?Forces are the definition of Newton's second law, which is stated under the relation:
∑ Force = mass × acceleration.
In other words, force is the origin of motion since it generates acceleration in a system.
In this case we must complete the statement:
"A student with mass 45 kg jumps off a high diving board. Using 6. 0×1024 kg for the mass of the earth, what is the acceleration of the earth toward her as she accelerates toward the earth with an acceleration of 9. 8 m/s2 ? assume that the net force on the earth is the force of gravity she exerts on it."
We determine the Force of the student:
F = ma
F = 45kg * 9.8m/s².
F = 441N
Now we go to the acceleration of the earth:
a = F/m
a = 441N / 6×10²⁴ Kg
a = 7.35×10-²³m/s².
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A Smart Car, which has a mass of 1000 kg, is going 20 m/s. When it hits the barrier, it stops at a time of 0.5 seconds. What is the impulse on the car?
Answer:
Imp = 20000 [kg*m/s]
Explanation:
In order to solve this problem we must divide it into two parts. In the first part we must use the following equation of kinematics.
[tex]V_{f}=v_{i}-a*t[/tex]
where:
Vf = final velocity = 0 (the car stops)
Vi = initial velocity = 20 [m/s]
a = acceleration [m/s²]
t = time = 0.5 [s]
Acceleration is negative as the cart slows down as it stops.
[tex]0=20-a*0.5\\20=0.5*a\\a=40 [m/s^{2}][/tex]
The second part is the determination of momentum, which is defined as the product of force over a given time. But to determine the force we must use Newton's second law which tells us that the sum of the forces of a body is equal to the product of mass by acceleration.
∑F = m*a
[tex]F = 1000*40\\F = 40000[N][/tex]
Now the impulse or momentum
[tex]Imp = F*t\\Imp = 40000*0.5\\Imp=20000[kg*m/s][/tex]
What limits the amplitude of motion of a real vibrating system that is driven at one of its resonant frequencies?
To find limits of the amplitude of motion of real vibrating system that is driven at one of its resonant frequencies, Here the damping of vibrations turns the energy of vibration into internal energy.
Two cats jump off a roof that is 23m off the ground. Cat A jumps directly up with a velocity of 7m/s, and cat B jumps directly down with a velocity of 7m/s. How far up does cat A go? How fast does cat A go just before it hits the ground? How fast does cat B go just before it hits the ground? How much longer is cat A in the air than cat B?
(1) The height reached by cat A is 2.5 m.
(2) The speed of cat A before it hits the ground is 36.4 m/s.
(3) The speed of cat B before it hits the ground is 22.39 m/s.
(4) The time spent in air by cat A than cat B is 1.43 seconds.
Time of motion of cat AThe time of motion of cat A is calculated as follows;
h = vt - ¹/₂gt
-23 = 7t - 4.9t²
4.9t² - 7t - 23 = 0
solve the quadratic equation using formula method;
a = 4.9, b = -7, c = - 23
t = 3.0 seconds
Time of motion of cat BThe time of motion of cat B is calculated as follows;
h = vt - ¹/₂gt
23 = 7t + 4.9t²
4.9t² + 7t - 23 = 0
solve the quadratic equation using formula method;
a = 4.9, b = 7, c = -23
t = 1.57 seconds
Height reached by cat Ah = u²/2g
h = (7²)/(2 x 9.8)
h = 2.5 m
Speed of cat A before it hits the groundv = u + gt
v = 7 + 3(9.8)
v = 36.4 m/s
Speed of cat B before it hits the groundv = u + gt
v = 7 + 1.57(9.8)
v = 22.39 m/s
Time spent in air by cat A than cat B
Time difference = 3 s - 1.57 s = 1.43 seconds
Thus, the height reached by cat A is 2.5 m.
The speed of cat A before it hits the ground is 36.4 m/s.
The speed of cat B before it hits the ground is 22.39 m/s.
The time spent in air by cat A than cat B is 1.43 seconds.
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Fossil fuels, hydroelectric power, and wind power ultimately get their energy from _______.
Fossil fuels, hydroelectric power, and wind power ultimately get their energy from sun.
Fossil fuels are hydrocarbons which are composed of carbon, hydrogen and oxygen. These are obtained from the decomposition of animals and organisms. The fossil energy almost came from the sun
Hydroelectric power is an indirect form of solar energy generated from water falling from high to low potential. It is a better alternative of electricity as it is environment friendly and do not release wastes, smoke and heat.
Wind power is renewable energy and generated from high speed wind. It is used to run wind turbines is a sustainable source of solar energy.
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A football is kicked at
a 51.0° angle, and hits the
ground 38.7 m away. What
was its initial velocity?
(Unit = m/s)
The correct answer is 19.7 m/s.
Range is the height of the projectile when it reaches a vertical velocity of zero; after that, gravity will take over and quicken the object's descent. The projectile range, which is determined by the object's initial velocity, is the horizontal displacement of the object projected.
Only when one force is applied at the start of the trajectory does projectile motion occur; thereafter, gravity is the only resistance. A projectile launched under specified beginning circumstances will have a range in physics. Assuming a flat Earth with a consistent gravity field and no air resistance may make it more predictable.
Range R = 38.7 m
Acceleration due to gravity g =9.8 m/s
Launch angle θ = 51
Range of the projectile is given by
R = [tex]u^2[/tex] Sin2θ / g
[tex]u^2[/tex] = gR/ Sin 2θ
u = √gR/ Sin 2θ
u = √ 9.8 × 38.7 / Sin ( 2 × 51)
u = 19.7 m/s.
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How do we determine the conditions that existed in the very early universe? A We can only guess at the conditions, since we have no way to calculate or observe what they were. B The conditions in the very early universe must have been much like those found in stars today, so we learn about them by studying stars. C From the current expansion rate we can work backward to estimate temperature and densities at various times in the early universe. D By looking all the way to the cosmological horizon, we can see the actual conditions that prevailed all the way back to the first instant of the Big Bang.
Answer:
D By looking all the way to the cosmological horizon, we can see the actual conditions that prevailed all the way back to the first instant of the Big Bang.
Explanation:
Astrophysicists are able to determine the conditions that existed in the early universe, by using instruments such as telescopes to observe and study cosmic horizons. More ideas about the early universe can be found from the thermal light present in cosmic backgrounds.
Scientists study these details that provide an insight into the conditions that existed so many years ago. They have been able to determine that the Big Bang involved so many collisions from these observations.
Which requires more work: lifting a 70 kg sack vertically 2 m or lifting a 35 kg sack vertically 4 meters?
Answer:
ADD ANSWER 5 PTS?
Explanation:
ME : Seriously
BRAINLY: 5 PTS!
Answer:
they require the same amount of work
Explanation:
the formula for work is
W=Fnet*Displacement
and Fnet =m*a
a=9.81 m/s^2
Which gives us
W=ma*d
The set up would be;
(35kg*9.81m/s^2)*4 m=W
(70kg*9.81m/s^2)*2m=W
W= 1373.4 J
Both are the same therefore the correcr answer is *both require the same amount of work*
Three solid plastic cylinders all have radius 2.50cm and length 6.00cm. Find the charge of each cylinder given the following additional information about each one. Cylinder (b) carries charge with uniform density 15.0 nC/m² on its curved lateral surface only. Cylinder
By the charge density, the curved surface area of the cylinder charge is 0.141 nC.
We need to know about charge density to solve this problem. The charge density can be determined as
λ = Q / A
where λ is charge density, Q is charge and A is surface area.
The parameter given is the charge density and the solid cylinder shape which are :
λ = 15 nC/m²
r = 2.5 cm = 0.025 m
L = 6.0 cm = 0.06 m
Find the curved surface area of cylinder
A = 2πrL
A = 2π. 0.025. 0.06
A = 9.43 x 10¯³ m²
Find the charges
Q = λ x A
Q = 15 x 9.43 x 10¯³
Q = 0.141 nC
Hence, the curved surface area of the cylinder charge is 0.141 nC.
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A ford F-250 pulls a 1000-kg car with a net force of 2000 N. What is the acceleration of the car A=F/m
Answer:
2ms^2
Explanation:
A = 2000 divided by 1000
A= 2
Newton’s laws of motion
2. A person lifts 200kg seven times over the course of 11.8s. If they displaced the weight 2.2m up each time, how much power did the person deliver?
Answer:
The person delivered a power of 2,558 Watt
Explanation:
Work and Power
Mechanical work is the amount of energy transferred by a force. It's a scalar quantity, with SI units of joules.
Being the force vector and the displacement vector, the work is calculated as:
[tex]W=\vec F\cdot \vec s[/tex]
If both the force and displacement are parallel, then we can use the equivalent scalar formula:
W=F.s
Power is the amount of energy transferred per unit of time. In the SI, the unit of power is the watt, equivalent to one joule per second.
The power can be calculated as:
[tex]\displaystyle P=\frac {W}{t}[/tex]
Where W is the work and t is the time.
If the person lifts a mass of m=200 Kg, then exerts a force equal to its weight:
F = m.g = 200*9.8 = 1,960
F = 1,960 N
The work done when lifting the weight 7 times by a distance of s=2.2 m is:
W = 7*1,960*2.2=30,184
W = 30,184 J
Finally, the power delivered in t=11.8 seconds is:
[tex]\displaystyle P=\frac {30,184}{11.8}[/tex]
P = 2,558 Watt
The person delivered a power of 2,558 Watt
GP Submarine A travels horizontally at 11.0 m/s through ocean water. It emits a sonar signal of frequency f = 5.27× 10³Hz in the forward direction. Submarine B is in front of submarine A and traveling at 3.00 m/s relative to the water in the same direction as submarine A. A crewman in submarine B uses his equipment to detect the sound waves ("pings") from submarine A. We wish to determine what is heard by the crewman in submarine B. (a) An observer on which submarine detects a frequency f' as described by Equation 17.19 ?
The frequency [tex]5.3 \times 10^3 \mathrm{~Hz}[/tex] that the submarine B detects a frequency f' as described by Equation 17.19.
Given:
Submarine A velocity, [tex]v_{s}=11\;m/s[/tex]
Submarine A Frequency, [tex]F = 5.27 \times 10^{3}\;Hz[/tex]
Submarine B velocity, [tex]v_{o}=3\;m/s[/tex]
As the sign of the submarine B frequency is positive. So, The submarine B is moving away from Submarine A. Therefore, The observer from submarine B detects the frequency [tex]f^{'}[/tex]
Using the Doppler Shift formula, we can determine the frequency of the sonar signal that the crewman in submarine B heard:
[tex]\begin{gathered}f_o=f_s\left(\frac{v-v_o}{v-v_s}\right), \\f_o=5.27 \times 10^3 \mathrm{~Hz} \cdot\left(\frac{1533 \frac{\mathrm{m}}{\mathrm{s}}-3 \frac{\mathrm{m}}{\mathrm{s}}}{1533 \frac{\mathrm{m}}{\mathrm{s}}-11 \frac{\mathrm{m}}{\mathrm{s}}}\right)=5.3 \times 10^3 \mathrm{~Hz} .\end{gathered}[/tex]
Hence, the frequency of [tex]5.3 \cdot 10^3 \mathrm{~Hz}[/tex] that the submarine detects a frequency f' as described by Equation 17.19.
What do you mean by Frequency?A frequency is the quantity of waves produced each second.
A measure of frequency is the number of times in a second that an alternating current (AC) changes from positive to negative. Direct currents do not experience this switching (DC). Hertz is used to measure frequency (Hz) The period is the length of time it takes for an AC current to start at zero, change from positive to negative, and then return to zero (i.e., the length of time it takes to complete one cycle), while the frequency is the reciprocal of the period. In contrast to low frequency, which has fewer waves per second but a longer period, high frequency refers to the number of waves per second and the length of the period.
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What is one result of warming up your bod'y muscles before exercising
Of there was no matter to vibrate, How will this affect a sound?
1. This sound would be louder.
2. The sound would have higher pitch.
3. There would be no sound.
4. The sound would have a lower pitch
Answer:
3. There would be no sound.
Explanation:
Sound is produced by vibrations that travel through a medium, most commonly through air.
If there is no matter to vibrate (such as in the vacuum of space) then there's no way for a sound wave to be produced.
Thus the answer is option 3. There would be no sound.
A dog runs after a ball that is 45 meters away. It takes him 9 seconds to reach the ball. How fast is the dog running?
Answer:
The answer in 5m/s
Explanation:
You use the formula s=d devided by t, so in other words, you devide 45 meters by 9seconds and the answer is 5m/s
If a persons skin is dry she will experience more of a shock
Answer:
add lotion
Explanation:
WILL MARK BRAINLIEST ONCE I KNOW THE RIGHT ANSWER *(AFTER THE FULL TEST)*
Rules:
DO NOT SCAM
DO NOT ANSWER IF YOU DO NOT KNOW
COMMENT RESPECTFULLY
Think back on what we have learned about gravity, mass, and weight. We are
going to take 5 minutes to write a 5-6 sentence reflection on what you learned
during this time. Make sure to use as many vocabulary words as you can.
Your answer
Answer: mass is both a property of a physical body and a measure of its resistance to acceleration when a net force is applied. An object's mass also determines the strength of its gravitational attraction to other bodies. weight is the weight of an object is the force acting on the object due to gravity. and gravity is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light—are brought toward one another.
Explanation: and that is mass weight and gravity
Part A
If you are not wearing a seat belt in a car that rounds a curve, and you slide across your seat and slam against a car door, what kind of force is responsible for your slide
centripetal, centrifugal, or no force?
O It is centrifugal force as viewed by someone outside the car.
There is no force as viewed by someone outside the car. To them you move in a straight line
O Centripetal force
It is centripetal force, but only as viewed by someone inside the car.
Answer:
I think it is the last option
Explanation:
which is the best description of a balanced stance
We know from experience that the harder we throw a ball (apply more force), the faster it will be
moving (greater initial velocity resulting from acceleration). If you throw a 1 kg softball as hard
as you can, and it is traveling at 20 m/s when it leaves your hand, how fast do you think a 5 kg
shot put would travel with the same throw?
The velocity the 5 Kg shot put would have, given the data from the question is 4 m/s
What is momentum?Momentum is defined as the product of mass and velocity. It is expressed as
Momentum = mass × velocity
How to determine the momentum of the 1 Kg ballWe'll begin by calculating the momentum of the 1 Kg ball. This can be obatined as follow:
Mass = 1 KgVelocity = 20 m/sMomentum = ?Momentum = mass × velocity
Momentum = 1 × 20
Momentum = 20 Kg.m/s
How to determine the velocity of the 5 Kg shot putMass = 5 KgMomentum = 20 Kg.m/sVelocity of 5 Kg = ?Momentum = mass × velocity
20 = 5 × velocity
Divide both sides by 5
Velocity = 20 / 5
Velocity of 5 Kg = 4 m/s
Thus, the 5 Kg shot put will have a velocity of 4 m/s
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Coach carver has created a new team game for his students to play it involves sprinting tagging and throwing a ball
Coach Carver has created a new team game for his students to play. It involves sprinting, tagging, and throwing a ball. Each team consists of 10 to 20 students. Which place is the safest to play the game
Answer:
Football Field
Explanation:
In sporting or gaming activities that involve sprinting, tagging, and throwing a ball. The safest place to play the game is "FOOTBALL FIELD"
This is because the football field is originally designed and created for footballing activities which are deemed spacious and free of danger. There is also evidence in the Olympic sporting activities.
Therefore, in this case, even though there is no option in the question, the correct answer is the Football field.
obtain derivatives of x/sinx
Answer:
[tex]\displaystyle \frac{x}{\sin x} = \sum^{\infty}_{n = 0} \frac{(2n + 1)!}{(-1)^nx^{2n}}[/tex]
General Formulas and Concepts:
Calculus
Differentiation
DerivativesDerivative NotationSequences
Series
Taylor Polynomials
MacLaurin Polynomial: [tex]\displaystyle P_n(x) = \frac{f(0)}{0!} + \frac{f'(0)}{1!}x + \frac{f''(0)}{2!}x^2 + \frac{f'''(0)}{3!}x^3 + \cdots + \frac{f^n(0)}{n!}x^n + \cdots[/tex]Power Series
Power Series of Elementary FunctionsMacLaurin SeriesTaylor SeriesExplanation:
*Note:
You could derive the Taylor Series for sin(x) using Taylor polynomials by differentiation by usually you have it memorized.
We want to obtain an infinite amount of derivatives of the given:
[tex]\displaystyle \frac{x}{\sin x}[/tex]
We know that a power series is defined as an infinite derivatives of a function. We know that the power series for sin(x) is:
[tex]\displaystyle \sin x = \sum^{\infty}_{n = 0} \frac{(-1)^nx^{2n + 1}}{(2n + 1)!}[/tex]
Divide x by the power series to obtain our derivatives:
[tex]\displaystyle \frac{x}{\sin x} = \sum^{\infty}_{n = 0} \frac{x}{\frac{(-1)^nx^{2n + 1}}{(2n + 1)!}}[/tex]
Simplify this down:
[tex]\displaystyle \frac{x}{\sin x} = \sum^{\infty}_{n = 0} \frac{(2n + 1)!}{(-1)^nx^{2n}}[/tex]
And we have our final answer.
Topic: AP Calculus BC (Calculus I + II)
Unit: Power Series
Radioisotopes often emit one or more types of radiation, including alpha particles, beta particles, and gamma rays. The distance the radiation travels through matter before being absorbed increases in order from alpha to gamma. Which statement describes the best radioisotope that can be used for radioisotope imaging and for radionuclide therapy?
A.It emits only gamma rays.
B.It emits only alpha particles.
C.It emits alpha and beta particles.
D.It emits beta particles and gamma rays.
The best radioisotope that can be used for radioisotope imaging and for radionuclide therapy is It emits beta particles and gamma rays.
What is and how does radiotherapy work?It is a treatment in which ionizing radiation (X-ray, for example) is used to destroy a tumor or prevent its cells from increasing. These radiations are not seen and during the application the patient does not feel anything. Radiation therapy can be used in combination with chemotherapy or other treatments.
in this case, the best radioisotope that can be used for imaging is radionuclide because It emits beta particles and gamma rays.
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Answer:
It emits beta particles and gamma rays.
Explanation:
Which model correctly represents the product or products of the chemical reaction?
The model that correctly represents the product or products of the chemical reaction is the first one. Thus, the correct option for this question is A.
What is a Chemical reaction?A chemical reaction may be defined as a type of reaction in which one or more substances that are known as the reactants are considerably converted to one or more different substances that are known as the products.
In a chemical reaction, the molecules or atoms of the substance may always remain the same in the reactant or product. That is the mass of the chemical substance may always remain the same. While model 2 and 4 increases the mass of compound A in the given reaction. So, they are eliminated.
Option 3 is incorrect because when you get a product of any chemical reaction, it may never be separated automatically as described in option C.
Therefore, the model that correctly represents the product or products of the chemical reaction is the first one. Thus, the correct option for this question is A.
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