why a dam is thicker at the bottom than it's top​

When a substance changes from one phase to another, which of the following events occurs (A) The substances loses or gains heat.

A Phase change is reversible physical change that happens when a substance changes from one state of matter to the another state of matter. when substances changes from solid , liquid or gas state to different state called as phase change. Temperature can change the substance from one phase to another. for example . we can freeze the water by putting it to freezer to change it into ice and when we put it on heat it changes to liquid.

Thus, When a substance changes from one phase to another, which of the following events occurs (A) The substances loses or gains heat.

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Answer:

The substance loses or gains heat.

Explanation:

Substances can be made to change phases by fluctuating the temperature, the pressure, or both

Mechanical kinetic energy is the energy of an object due to its motion.

a) Mechanical kinetic energy = (1/2)*mass*(velocity)^2

Mechanical kinetic energy = (1/2)*(6.80 x 10^3 kg)*(23.7 m/s)^2

Mechanical kinetic energy = 3.27 x 10^7 J

b) The mechanical kinetic energy of a moving object can be calculated using the following formula:

KE = 0.5 * m * v²,

where m is the mass of the object and v is the velocity.

In this case, we know the mass of the family car (1237 kg) and the mechanical kinetic energy of the box car (50444 J). To calculate the speed of the family car, we can rearrange the formula to solve for v:

v = √(2*KE/m)

v = √(2*50444/1237)

v = 42.62 m/s

What is Mechanical kinetic energy?

Mechanical kinetic energy is the energy associated with the movement of a body or object. It is also known as the energy of motion and is equal to one half of the mass of the object multiplied by the square of its velocity.

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z₂ is equal to the negative of z₁.

Let's assume that the two non-zero complex numbers are represented in polar form as:

z₁ = r(cosθ₁ + i sinθ₁)

z₂ = r(cosθ₂ + i sinθ₂)

where r = |z₁| = |z₂| is the magnitude of both complex numbers, and θ₁ and θ₂ are their arguments.

From the given condition, we have:

arg(z₁) + arg(z₂) = π

Substituting the polar forms of z₁ and z₂ into the equation above, we get:

arctan(sinθ₁/cosθ₁) + arctan(sinθ₂/cosθ₂) = π

Simplifying this expression, we get:

θ₁ + θ₂ = π (Note that cosθ₁ and cosθ₂ are both positive because |z₁| = |z₂|, so we can use the arctan identity for the sum of two angles)

Rearranging this expression, we get:

θ₂ = π - θ₁

Substituting this into the polar form of z₂, we get:

z₂ = r(cos(π - θ₁) + i sin(π - θ₁))

z₂ = r(-cosθ₁ - i sinθ₁)

z₂ = -z₁

Therefore, z₂ is equal to the negative of z₁.

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Complete question is: z₁ and z₂ are two non-zero complex number such that |z₁|=|z₂| and argz₁ + argz₂ = π then z₂ equals​ to the negative of z₁.

Answer:

Unsaturated Solution: Less amount of salt in water, clear solution, no precipitation. Saturated Solution: The maximum amount of salt is dissolved in water, Colour of the solution slightly changes, but no precipitation. Supersaturated Solution: More salt is dissolved in water, Cloudy solution, precipitation is visible.

Answer:

  h = 1.3 m

Explanation:

For this exercise we can use the relationship between work and kinetic energy

          W = Δx = K_f - K₀

in the exercise they indicate that the strength of the athlete is over twice his weight, therefore the ratio of the floor directed upwards has the same value

           F = 2W

           F = 2 mg

the displacement is x = 0.65 m, note that the direction of the force and the displacement is the same and the initial velocity is zero due to being crouched at rest, we substitute

          F x = ½ m v² - 0

         v² = 2 (2mg) x / m

         v = \(\sqrt{4gx}\)

let's calculate

          v = \(\sqrt{ 4 \ 9.8 \ 0.65}\)

          v = 5.05 m / s

already in the air energy is conserved

starting point. Just when it comes off the ground

         Em₀ = K = ½ m v²

final point. When is it at the highest part of the trajectory

          Em_f = U = m g h

          Em₀ = Em_f

          ½ m v² = m g h

           h = ½  \(\frac{v^2}{g}\)

let's calculate

           h = ½ 5.05²/9.8

           h = 1.3 m

Explanation:

Yes, there are differences in the shapes of position-time graphs for uniform acceleration and uniform deceleration in different directions. Let's consider each case separately:\(\hrulefill\)

(1) - Uniform acceleration towards the positive direction:

In this case, the object is moving in the positive direction with a constant acceleration. The displacement-time graph will typically be a curve that starts from an initial position and shows a steady increase in displacement over time. The shape of the graph will depend on the specific acceleration value.

(2) - Uniform acceleration towards the negative direction:

In this case, the object is moving in the negative direction with a constant acceleration. The displacement-time graph will also be a curve, but it will show a steady decrease in displacement over time.

(3) - Uniform deceleration towards the positive direction:

In this case, the object is initially moving in the positive direction but is slowing down with a constant deceleration. The displacement-time graph will be a curve that starts with a positive slope and gradually levels off.

(4) - Uniform deceleration towards the negative direction:

In this case, the object is initially moving in the negative direction but is slowing down with a constant deceleration. The displacement-time graph will be a curve that starts with a negative slope and gradually levels off.

Answer:

2.29 s

Explanation:

This problem is a description of an elastic collision (the two objects collide and effectively become one object).  The equation for an elastic collision is

\(m_1v_1+m_2v_2=m_3v_3\), where:

\(m_1v_1\) = the mass of the child (55.0 kg) times the velocity of the child (2.5\(\frac{m}{s}\))

\(m_2v_2\) =  the mass of the sled (12.0 kg) times the velocity of the sled (0.0\(\frac{m}{s}\))

\(m_3v_3\) = the combined mass of the child and the sled (67.0 kg) times the combined velocity of the child and the sled (\(v_3\))

First, rearrange the problem to solve for \(v_3\):

\(\frac{m_1v_1+m_2v_2}{m_3}=v_3\)

So,

\(\frac{(55.0\ kg)(2.5\ \frac{m}{s})+(12.0\ kg)(0.0\ \frac{m}{s})}{67.0\ kg}=v_3\\\frac{137.5\frac{kg*m}{s}}{67.0\ kg}=v_3\\2.05\frac{m}{s}=v_3\)

The force of friction for this problem is given as 60 N.  To stop the child and the sled, the force of friction must be equal and opposite to the force of the child and sled.  According to Newton's first law, force equals mass times acceleration (F=ma).  So, an equation to solve this portion of the problem can be given as -60 N=ma, where m=67.0 kg.  So,

\(-60\ N=(67.0\ kg)a\\\frac{-60\ \frac{kg*m}{s^2}}{67.0\ kg}=a\\-0.90\frac{m}{s^2}\)

Acceleration can then be used in kinematic equation #1 (\(v_f=v_i+at\)) to solve for time.  Rearrange the equation and let

\(v_f=0.0\frac{m}{s}\\v_i=2.05\frac{m}{s}\\a=-0.90\frac{m}{s^2}\)

So,

\(\frac{v_f-v_i}{a}=t\\\frac{0.0\frac{m}{s}-2.05\frac{m}{s}}{-0.90\frac{m}{s^2}}=t\\\frac{-2.05\frac{m}{s}}{-0.90\frac{m}{s^2}}=t\\2.29\ s=t\)

Bài i:NPPPPNP

Explanation:

ppnp

A significant meteoroid collision caused the meteor crater to develop. The right response is option c.

A meteor is a streak of light in the sky that results from a meteoroid colliding with Earth's atmosphere. Meteoroids are rock or iron clusters that orbit the sun.

Meteor Crater, located close to Winslow, Arizona, is one of the most well-known craters on Earth. A 50-meter (164-foot), 150,000-ton meteorite fell into the desert roughly 50,000 years ago, instantaneously creating the crater. The diameter and depth of Meteor Crater are 1.2 km (0.75 miles) and 175 m (575 feet), respectively.

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--The complete question is, which of the following are possible explanations for the formation of the meteor crater?

a. volcanic explosion

b. a large pothole formed by swirling water action in an extremely large river

c. large meteoroid collision--

Two forces acting on the rocket immediately after leaving the launching pad are the gravitational force and the thrust force.

1. Gravitational Force: The gravitational force is the force exerted by the Earth on the rocket due to their mutual gravitational attraction. It acts downward and is responsible for the rocket's weight.

This force can be represented by the equation Fg = mg, where Fg is the gravitational force, m is the mass of the rocket, and g is the acceleration due to gravity. The gravitational force acts to pull the rocket downward, opposing its upward motion.

2. Thrust Force: The thrust force is the force generated by the rocket's engines as they expel exhaust gases in the opposite direction. It acts upward and propels the rocket forward.

The magnitude of the thrust force depends on factors such as the design of the rocket engines, the amount of fuel burned, and the rate of exhaust gas expulsion. The thrust force must be greater than or equal to the gravitational force for the rocket to overcome Earth's gravity and achieve upward acceleration.

Initially, when the rocket is launched, the thrust force is at its maximum while the gravitational force remains constant. As the rocket gains altitude, the gravitational force decreases slightly due to the increasing distance from the Earth's center.

However, the thrust force continues to be the dominant force propelling the rocket upward.

It's important to note that other forces such as air resistance and wind may also act on the rocket, but immediately after leaving the launching pad, these forces are typically negligible compared to the gravitational force and thrust force.

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Answer: A flower pot falling

Explanation:

The car on the curve (its direction is changing) and the falling flower pot (its speed is changing) are both undergoing acceleration.

The correct measuring tool is a Graduated cylinder. The correct option is B

Tangential speed refers to the linear speed or velocity of an object along its circular path, specifically in the direction tangent to the circle. It represents how fast an object is moving along the circumference of the circle at a given point.

The other options are not suitable for measuring the time it takes for the toy to complete one revolution around the circle for the following reasons:

A) Force probe: A force probe is used to measure forces, not time. It would not provide accurate timing information for the toy's revolution.

C) Meterstick: A meterstick is used to measure lengths and distances. It cannot directly measure time, which is required to determine the time for one revolution.

D) Spring scale: A spring scale is used to measure forces. It would not provide accurate timing information for the toy's revolution.

On the other hand, a graduated cylinder is a cylindrical container with markings indicating volume. While it is primarily used for measuring the volume of liquids, it can also be used as a timing tool in this scenario. By filling the graduated cylinder with a known volume of liquid and placing it under the toy's path, the time it takes for the toy to complete one revolution can be measured by observing the displacement of the liquid level in the graduated cylinder over time.

Therefore, the correct answer is option B.

The question is incomplete , I think the question is,

One end of a string is attached to the ceiling - with the other end attached to toy. The toy can be set into motion such that travels in horizontal circular path , constant tangential speed as shown above: Which of the following measuring tools could be used to determine the time it takes for the toy to complete one revolution around the circle? String

A) Force probe

B) Graduated cylinder

C)Meterstick

D) Spring scale Toy

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(b)

Explanation:

Energy levels farther from the nucleus represent higher energies. Therefore, in order for the electrons to reach these levels, they must absorb additional energies first before they can make the jump.

A Stone Is Dropped Into a Deep Water Well. The Sound of The Stone Hitting The Water Is Heard After 3.4 Seconds. then The Depth of The Water Well is 56.6 m.

In terms of physics, sound is a vibration that travels through a transmission medium like a gas, liquid, or solid as an acoustic wave. Sound is the receipt of these waves and the brain's perception of them in terms of human physiology and psychology. Only acoustic waves with frequencies between about 20 Hz and 20 kHz, or the audio frequency range, may cause a human to have an auditory sensation. These correspond to sound waves in air with an atmospheric pressure of 17 metres (56 ft) to 1.7 centimetres (0.67 in) in wavelength. Ultrasounds are sound waves with a frequency higher than 20 kHz that are inaudible to humans. Infrasound refers to sound frequencies below 20 Hz. Animals of different species have different hearing ranges. Acceleration of the stone is 9.8 m/s²

according to kinematics,

s = ut + 1/2 at²

s =  1/2 ×9.8×3.4²

s = 56.6 m

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Answer:

Approximately \(9\; {\rm N \cdot m^{-1}}\).

Explanation:

Change in the gravitational potential energy (GPE) of the system:

\((\text{change in GPE}) = m\, g\, \Delta h\), where:

Change in the elastic potential energy (EPE) of the system:

\(\text{(change in EPE)} = (1/2)\, k\, x^{2}\), where:

Set \(\text{(change in GPE)} = \text{(change in EPE)}\) and solve for the spring constant \(k\):

\(\displaystyle m\, g\, \Delta h = \frac{1}{2}\, k\, x^{2}\).

\(\begin{aligned}k &= \frac{m\, g\, \Delta h}{(1/2)\, x^{2}} \\ &= \frac{(115)\, (9.8)\, (250)}{(1/2)\, (250)^{2}}\; {\rm N\cdot m^{-1}} \\ &\approx 9\; {\rm N\cdot m^{-1}}\end{aligned}\).

Answer:Correct option is B)

In horizontal direction, two forces are acting on the block : 100 N force and friction force (f)

f=μN=μmg=0.5×10×10=50N

So, net force acting on the block in horizontal direction = 100 N-50 N = 50 N

acceleration of the block = Net force / mass of block = 50 N/10 kg = 5 ms

−2

Solve any question of Laws of Motion with:-

Explanation:

The magnetic field protect life on Earth by directing the charged particles toward the poles and then past Earth.

The giant shield around Earth that protects all living things from dangerous charged particles from the sun is called as Earth's magnetosphere. It is generated by the motion of molten iron in Earth's core. It also provides the basis for navigation using a compass.

The magnetosphere shields the life on Earth from the constant bombardment by charged particles emitted from the sun which is called as solar wind.

Therefore, the magnetic field protects life on Earth by directing the charged particles toward the poles and then past Earth.

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Sound waves are a type of mechanical wave that propagate through a medium, typically air but also other materials such as water or solids.

Frequency: the frequency of a sound wave refers to the number of cycles or vibrations it completes per second and is measured in Hertz (Hz).

Amplitude: the amplitude of a sound wave refers to the maximum displacement or intensity of the wave from its equilibrium position. It represents the loudness or volume of the sound, with larger amplitudes corresponding to louder sounds and smaller amplitudes corresponding to softer sounds.

Wavelength: the wavelength of a sound wave is the distance between two consecutive points in the wave that are in phase, such as from one peak to the next or one trough to the next. It is inversely related to the frequency of the wave.

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Answer:

A. The fugacity in the vapor phase at T = 323 K and P = 10 kPa:

Explanation:

The impact of the imagery used in paragraph six on the meaning of "On a Mountain Trail" emphasizes the fear and uncertainty of the narrator as the pack surrounds the sleigh on the trail.

The imagery in paragraph 6 paints a vivid and powerful picture of a pack of wolves surrounding the sled. Because of the narrator's inability to count the number of wolves present, this description adds to the feeling of anxiety and uncertainty. The scene reinforces the emotional impact of the scene and helps convey the protagonist's sense of vulnerability and danger.

Therefore, the correct option is C.

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Answer:

A. it remains the same

Explanation:

Answer:

11948.64 Newtons

Explanation:

Answer:

When waves travel from one medium to another the frequency never changes. As waves travel into the denser medium, they slow down and wavelength decreases. Part of the wave travels faster for longer causing the wave to turn. The wave is slower but the wavelength is shorter meaning frequency remains the same.

Explanation:

Answer:

14.764 (rounded to the nearest thousandths)

Explanation:

Reminder: displacement is the length of the shortest line you can draw from the original point to your current point.

In this case, we can use the pythagorean theorem, where c is the displacement:

8.86^2+11.81^2=c^2

217.9757=c^2

c≈14.764 (rounded to the nearest thousandths)

The total time required is 1 minute and 0.3 seconds.

Assumption: The distance between the people is 1 m and the stadium is a circle with a radius of 100m.

Here, the time taken by the person is 0.1 seconds.

Total distance covered by the wave = Circumference of the circle

So, total distance = 2 πr = 2 × 3.14 × 100 = 618 m

As the distance between each of the people is 1 m.

So, the number of personal interactions is 618.

Time taken by each person is 0.1 seconds.

So, total time, t = 0.1 × 618 = 61.8 seconds.

So, the order of the magnitude of the time required is 1 minute and 0.3 seconds for such a pulse to make one circuit around BC Place Stadium in Vancouver.

Hence, the total time required is 1 minute and 0.3 seconds.

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The angle between the reflected and refracted rays is the same as the angle of incidence, which is 48.0°. This is because of the law of reflection.

Reflection is the process of actively and critically considering an experience or event in order to gain a deeper understanding of it. Reflection can be a powerful tool for personal growth and development, helping us to take control of our lives and make positive changes. Reflection involves analyzing and interpreting our thoughts and feelings about an experience, and can be done through writing, talking, or thinking. It is a way of exploring our beliefs, values, and assumptions, and is often used to explore our emotions, behaviours, and relationships.

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Answer:

It you get a sushi for work, for a party, then it leads to people being happy, as an independant variable

It is changing the molecular structure of a protein

Explanation:

Scattering is the process of deflection of radiation due to interaction with the particle.

Thus option C: scattering is correct.