A train accelerated from 20km/hr to 80km/hr in 4 minutes. How much distance does
it cover in this period? Assume that the tracks are straight?

Answer:That only applies to highly polished surfaces, eg mirrors.

If you take a high quality laser (ie with low divergence) and aim it at a wall, you can see the spot where the laser beam reaches the wall from anywhere with a direct line-of-sight to the spot where the laser beam reaches the wall. This due to micro imperfections on the surface of the wall. At a microscopic level, the wall surface is very rough and pointing in all directions.

As to why, a beam of light bounces of a highly polished surface, I can only surmise that it is essentially due to kinematics, ie the only force opposing the light beam is normal to the surface, hence there no forces along the reflective surface. Since there are no forces along the reflective surface, the speed component of light along the reflective surface remains unchanged. However, on the plane perpendicular to the reflective surface the, the light photons bounce off at the same speed at which the hit the reflective surface because the mass of the reflective surface is much much much larger than the mass of the photons, which means that the reflective surface won’t move at all. Since conservation of momentum requires that momentum after the collision be the same as the momentum before the collision then the only way for that to happen is if the velocity of the photon perpendicular to the reflective surface is of exactly the same magnitude but in the opposite direction. Vector resolution of the speed component of the reflected beam means that the angle of reflection must be the same as the angle of incidence.

Explanation:

Lοwell Observatοry, where Clyde Tοmbaugh discοvered Plutο in 1930, is lοcated in the state οf Arizοna, United States.

Arizοna, alsο knοwn as the Grand Canyοn State, is lοcated in the sοuthwestern regiοn οf the United States. It shares bοrders with Califοrnia, Nevada, Utah, New Mexicο, and Mexicο. The state is knοwn fοr its diverse geοgraphy, which includes deserts, canyοns, mοuntains, and fοrests.

The capital and largest city οf Arizοna is Phοenix. It is a vibrant and rapidly grοwing metrοpοlitan area. Other majοr cities in the state include Tucsοn, Mesa, Scοttsdale, and Flagstaff.

Arizοna has a rich Native American histοry and is hοme tο variοus Native American tribes, including the Navajο, Hοpi, and Apache. The state has a deep cultural heritage, and yοu can find numerοus archaeοlοgical sites and ancient cliff dwellings thrοughοut the regiοn.

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The direction of the magnetic force that the vertical rod exerts on the horizontal rod depends on the orientation of the magnetic fields of the two rods.

If the magnetic fields are aligned in the same direction, the net magnetic force will be attractive, pulling the two rods together. If the magnetic fields are aligned in opposite directions, the net magnetic force will be repulsive, pushing the two rods apart. In either case, the direction of the net magnetic force will be perpendicular to both the direction of the magnetic fields and the direction of the rods.

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It's true that air resistance is really low. Energy must not be gained or lost during the experiment if they expect to demonstrate that energy is conserved. In other words, there must be little loss from air resistance.

Air is the source of the force known as air resistance. An object travelling through the air experiences the force in the opposite direction. A sports vehicle with a streamlined form will face less air resistance than a lorry with a flat front, enabling the latter to travel faster.

The force of air resistance changes depending on the velocity. This implies that the acceleration is not constant and neither is the force. That is a serious issue.

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A diode is a two terminal device that passes and blocks the current.

A diode is a semiconductor gadget that essentially switches current in a single direction.

However, it substantially inhibits current flow in the opposite direction. It permits an easy flow of current in one direction.

Due to the fact that they convert alternating electricity into pulsing direct current, diodes are sometimes referred to as rectifiers. Type, voltage, and current capability are used to rate diodes.

The anode and cathode determine the polarity of diodes. The majority of diodes only permit current to flow when the anode is subjected to positive voltage.

A diode is forward-biased when it permits current flow. Reverse-biased diodes function as insulators.

The arrow of the diode symbol points away from the direction of electron flow. The symbol was created by engineers, whose current flowed in a positive direction.

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An inquisitive physics student and mountain climber climbs a 41.9 m cliff that overhangs a calm pool of water. It takes 2.996 seconds for the stone to hit the water.

We set \(y_i = 0\) at the top of the cliff, and find the time interval required for the first stone to reach the water using the particle under the constant acceleration model:

\(y_f = y_i + v_{yi}t+ \frac{1}{2} a_yt^2\)

OR

\(y_f -y_i - v_{yi}t- \frac{1}{2} a_yt^2 = 0\)

OR

\(- \frac{1}{2} a_yt^2 - v_{yi}t+y_f-y_i=0\)

If we take the direction downward to be negative,

\(y_f = -41.9 m, v_{yi} = -2 m/s, a_y = 9.8 m/s^2\)

Substituting these values into the equation, we find

4.9t² + 2t - 50 = 0

The quadratic formula is now what we use. Since the stone is thrown into the pool, time must be positive, and the physical situation can only be described by the positive root:

\(t = \frac{-2 \pm\sqrt{2^2 - 4(4.9)(-41.9)} }{2(4.9)}\)

⇒ t = 2.996 sec

Therefore, it takes 2.996 seconds for the stone to hit the water.

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Answer:

If all the heat energy contained in a body is removed and changes in its temperature is described below in detail.

Explanation:

It moves from a body at a greater temperature to a body at a cheaper temperature. All element survives as solids, liquids, or gases. The material can transfer from one station to another if warmed or cooled. When heat is provided to a body its heat increases: When a physical body, hard, liquid. When heat is provided is stopped to a body its temperature decline.

To find the amount of ice melted and the final temperature when steam at 100°C is added to ice at 0°C, we can use the principles of heat transfer.

First, let's determine the heat transferred when the steam condenses to water at 100°C.

This can be calculated using the equation: Q = m * Lf

where Q is the heat transferred, m is the mass, and Lf is the latent heat of fusion for water, which is 334 J/g.

Given that the mass of steam is 10.0 g, the heat transferred is:

Q = 10.0 g * 334 J/g = 3340 J

Next, let's determine the heat required to heat the ice to its melting point at 0°C. This can be calculated using the equation:

Q = m * Cp * ΔT

where Q is the heat transferred, m is the mass, Cp is the specific heat capacity of water, and ΔT is the change in temperature.

The specific heat capacity of ice is 2.09 J/g°C. The change in temperature is: ΔT = 0°C - (-100°C) = 100°C

Therefore, the heat transferred is: Q = 50.0 g * 2.09 J/g°C * 100°C = 10,450 J

To find the final temperature, we can equate the heat transferred during condensation to the heat transferred to raise the ice's temperature: 3340 J = 10,450 J

The ice will melt completely, resulting in a final temperature of 0°C. In conclusion, when 10.0 g of steam at 100°C is added to 50.0 g of ice at 0°C, all the ice will melt, and the final temperature will be 0°C.

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Answer:

Approximately \(1.5\; {\rm s}\).

(Assumptions: \(g = 9.81\; {\rm m\cdot s^{-2}}\); air resistance on the volleyball is negligible.)

Explanation:

Under the assumptions, acceleration of the volleyball would be \(a = (-g) = (-9.81)\; {\rm m\cdot s^{-2}}\) during the entire flight. (This value is negative since the ball is accelerating downwards- toward the ground.)

By the time the volleyball hits the ground, the volleyball would be at a position \(2.0\; {\rm m}\) below where it was launched. In other words, the (vertical) displacement of the volleyball during the entire flight would be \(x = (-2.0)\; {\rm m}\). (Negative since the ball is below where it was launched.)

Apply the SUVAT equation \((v^{2} - u^{2}) = 2\, a\, x\) to find the velocity of the volleyball right before hitting the ground. In this equation:

Rearrange this equation and solve for the velocity right before landing, \(v\). Note that because \(v\!\) is raised to the power of \(2\) in \((v^{2} - u^{2}) = 2\, a\, x\), both \(v = \sqrt{u^{2} + 2\, a\, x}\) and \(v = -\sqrt{u^{2} + 2\, a\, x}\) could satisfy this equation. However, \(v\!\!\) needs to be negative since the volleyball would be travelling downwards before reaching the ground.

Therefore, right before reaching the ground, velocity of the volleyball would be:

\(\begin{aligned} v &= -\sqrt{u^{2} + 2\, a\, x \\ &= -\sqrt{(6.0)^{2} + 2\, (-9.81)\, (-2.0)} \; {\rm m\cdot s^{-1}} \\ &\approx (-8.67)\; {\rm m\cdot s^{-1}}\end{aligned}\).

In other words, velocity of this volleyball has changed from \(u = 6.0\; {\rm m\cdot s^{-1}}\) (upwards) to \(v \approx (-8.67)\; {\rm m\cdot s^{-1}}\) (downwards) during this flight. Divide the change in the velocity \((v - u)\) by the rate of change in velocity \(a = (-9.81)\; {\rm m \cdot s^{-2}}\) to find the duration of this flight:

\(\begin{aligned}t &= \frac{v - u}{a} \\ &\approx \frac{(-8.67) - 6.0}{(-9.81)}\; {\rm s} \\ &\approx 1.5\; {\rm s}\end{aligned}\).

freezing

During freezing, the temperature of a substance remains constant while the particles in the liquid form a crystalline solid. Because particles in a liquid have more energy than particles in a solid, energy is released during freezing. This energy is released into the surroundings.

The acceleration of the crate is 1.196 m/s².

This can be defined as the rate of change of velocity.

To calculate the acceleration of the crate, we use the formula below.

Formula:

Where:

From the question,

Given:

Substitute the values above into equation 1

Hence, The acceleration of the crate is 1.196 m/s²

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Answer:

B. A hill 70ft tall.

Explanation:

Answer:

I would assume that the box slows down due to the frictional force between the floor and the box. In addition, the frictional force points opposite of the boxes motion. As we know, the box was given an initial speed, therefore, having an applied force. Hence, we can conclude that  the frictional force opposing the motion of the crate is equal to the applied force but acting in the opposite direction. This frictional force is called static friction. When we increase the applied force (push harder), the frictional force will also increase until it reaches a maximum value.

Hope that helps!

Explanation:

The relationship among u, v, and f in the context of a lens can be described by the lens formula:

1/v - 1/u = 1/f

where:

- u is the object distance (distance between the object and the optical center of the lens),

- v is the image distance (distance between the image and the optical center of the lens), and

- f is the focal length of the lens.

According to the lens formula, the reciprocal of the image distance subtracted from the reciprocal of the object distance is equal to the reciprocal of the focal length.

Atoms interact and form chemical bonds through its various components: valence electrons, protons, the nucleus of each atom, and the orbitals.

Here, all the options are correct.

These components are essential for atoms to interact and form bonds, as they provide the crucial energy and direction for the reaction. Valence electrons contain the most energy and are most available for reacting. These electrons are the outer shell and provide the electrons needed to form a bond with another atom.

This process creates a stable bond between atoms, and can be observed when an atom has an incomplete outer shell of electrons (an incomplete electron valence shell).Protons and the nucleus of each atom provide the matter for a bond between two atoms.

The nucleus of an atom has a “charge”, either a positive or neutral, and the protons within the nucleus contribute to the overall charge of the atom. Finally, the orbitals are important for allowing two atoms to interact and form a bond. Orbitals are the “region” in space around an atom where electrons have the highest probability of being found.

Here, all the options are correct.

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Answer:hhahe

Explanation:

The gravitational potential energy of a falling apple is similar to the potential difference of a battery because both are energy stored in the object

The gravitational potential energy of a falling apple is maximum when the apple is at maximum height. As the apple begins fall to the ground the potential energy decreases and it will be transformed to kinetic energy.

\(P.E_i + K.E_i = P.E_f + K.E_f\)

The potential difference in a battery is total energy stored in the battery.

Thus, the gravitational potential energy of a falling apple is similar to the potential difference of a battery because both are energy stored in the object.

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The similarity is that both the battery and the falling apple have stored energy.

We define the potential energy of an object as stored energy in that object.

A battery has potential energy, it is stored until you connect it to something and allow that energy to flow.

Similarly, when the apple is in the air it has potential energy, that will be transformed into kinetic energy as it falls (as the apple falls, its velocity increases, thus, the kinetic energy increases).

So both, the apple and the battery have stored energy, and that is the similarity between these two.

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Answer:

These has anwers and also the solution. You can recheck if you want.

As you stretch the band a distance x, the force you need to exert has a magnitude of (250 N/m) x.

So if 100 N is required to stretch it to maximum length, then this length is x such that

100 N = (250 N/m) x   ==>   x = (100 N)/(250 N/m) = 0.4 m

Answer:

0.6

Explanation:

I got it right

The acceleration of the airboat  is 2.2m/s^2 and starting from rest, it take the airboat to reach a speed of 12.0 m/s is 5.45s

Given mass of airboat (m) = 3.50 x 10^2kg

horizontal force of engine (F) = 7.70 x 10^2N

We know that from newtons laws of motion Force = mass x acceleration such that F = ma

(a) Now a = F/m = 7.70 x 10^2 / 3.50 x 10^2 = 2.2m/s^2

(b) Initial speed of airboat (u) = 0m/s

final speed (v) = 12m/s

We have acceleration a = 2.2m/s

Then we have another newtons law as: v = u+ at where t is the time taken

So t = v/a = 12/2.2 = 5.45s

Hence it takes to reach 5.45s a speed of 12m/s

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Answer:

4

Explanation:

Answer:

i am pretty sure that it is 4

The frequency is the number of waves that traverse a spot in a specific amount of time.

the quantity of times something happens in a certain amount of time. -the number of waves passing a point per second is the frequency of a wave. - The hertz is a measure of frequency ( Hz ). One event occurs every second in a hertz. Shorter wavelengths will equate to lower frequencies if the speed is remained constant.

The frequency of a wave determines its properties. The quantity of waves that pass through a specific spot in a unit of time is known as frequency. Hertz is the S.I. unit for frequency (Hz).

For instance, if a wave travels through a spot in 0.5 seconds, its frequency will be 1 0.5 = 2 Hz.

As a result, two waves will go through that location in a second.

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Answer: Thunderstorm.

Explanation: When a cold, dry air mass collides with a warm, humid air mass over the land, that's a tornado, but on top of that the air rises and it cools and condenses that's a thunderstorm

When a cold, dry air mass collides with a warm, humid air mass over the land, that's a tornado, but on top of that the air rises and it cools and condenses that's a thunderstorm.

A thunderstorm, sometimes referred to as an electrical storm or a lightning storm, is a type of storm that is distinguished by the presence of lightning and the thunder that results from the lightning's acoustic effect on the Earth's atmosphere.  

Thundershowers are the name for relatively weak thunderstorms. A cumulonimbus is a form of cloud where thunderstorms develop.  They frequently produce heavy rain.  and occasionally snow, sleet, or hail and they are typically accompanied by strong wind.

However, some thunderstorms result in little or no precipitation. A squall line, often known as a succession of thunderstorms, can form or become a rainband.

Therefore, When a cold, dry air mass collides with a warm, humid air mass over the land, that's a tornado, but on top of that the air rises and it cools and condenses that's a thunderstorm.

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The distance from the base of the cliff to the point on the ground is approximately 4047 ft when rounded to the nearest foot.

To find the distance from the base of the cliff to the point on the ground, you can use the tangent function in trigonometry. Let's denote the distance we want to find as "x".

We know the angle of depression is 7 degrees and the height of the cliff is 498 ft.

The tangent function is given by tan(θ) = opposite/adjacent, where θ is the angle, the opposite side is the height of the cliff, and the adjacent side is the distance we want to find (x).

Therefore, we can write the equation: tan(7°) = 498/x.

To find the value of x, we can rearrange the equation: x = 498/tan(7°).

Now, we can plug in the angle and calculate the distance:

x = 498/tan(7°) ≈ 4046.56 ft

Therefore, the distance from the base of the cliff to the point on the ground is approximately 4047 ft when rounded to the nearest foot.

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The complete question is:

An observer at the top of a 498 ft cliff measures the angle of depression from the top of the cliff to a point on the ground to be 7 degrees. What is the distance from the base of the cliff to the point on the ground? Round to the nearest foot.

When Laser shines on screen being passed through two closely spaced slits we see interference.

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The maximum distance a wave varies from its rest position is called the amplitude of the wave.

The amplitude represents the maximum displacement or distance from equilibrium that a particle or medium experiences as the wave passes through it.In a transverse wave, such as a wave on a string or an electromagnetic wave, the amplitude is measured as the maximum displacement of the particles in the medium perpendicular to the direction of wave propagation. For example, in an ocean wave, the amplitude would be the maximum height of the wave crest above the average water level.

In a longitudinal wave, such as a sound wave, the amplitude is measured as the maximum displacement of particles in the medium parallel to the direction of wave propagation. For example, in a sound wave, the amplitude would be the maximum compression or rarefaction of air particles from their equilibrium position.

The amplitude of a wave determines its energy and intensity. Higher amplitudes generally correspond to waves with greater energy and intensity. Amplitude also affects the perception of the wave, such as the volume of a sound wave or the brightness of a light wave.

It's important to note that the amplitude is a measure of the wave's displacement and should not be confused with wavelength, which is the distance between two corresponding points on the wave (e.g., crest to crest or compression to compression).

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Answer: Increases, decreases

Explanation:

As the volume of a chamber decreases the pressure inside the chamber increases. As the volume increases the pressure decreases

Answer:

38 years old.

Explanation:

So, we are given the following data or parameters or information which is going to assist us in solving this particular Question;

1=> The three children are A, B and C respectively.

2=> "the present age of husband is 5 years more than the wife's age."

3=> " the wife's age is twice the present age of A"

4=> the present age of A is 12 years more than the present age of B "

5=> B's present age is one and a half times the present age of C .

6=> "if C is 12 years old at present "

7=> "husband's friend Ram who is 15 years younger than the husband"

We will start from point 5 above that is to say;

B = C × 3/2. = 12 × 3/2 = 6 × 3= 18.

Also, A = 12 + B = 12 + 12= 24.

From the point 3 Above; the wife's age= 2 × A= 2 × 24 = 48 years of age.

From the point 2, we have that the husband's age = 5 + 48 = 53 years of age.

Thus, the present age of husband's friend, Ram who is 15 years younger than the husband = 53 - 15 = 38 years old