Is a bird sitting motionless on a perch, balanced or unbalanced?

A brass rod is encased in aluminium. The speed of a sound wave decreases when it moves from the aluminium into the brass. Thus, the correct option is B.

The speed of sound is the speed with which sound travels in a medium. It depends on the density and the elasticity of the medium through which the sound waves travel. In general, sound wave travels faster in the liquid mediums than in gas medium and these are quicker in solids than in liquid mediums. The greater the elasticity and the lower the density of the waves, the faster the sound waves travel in a medium.

The speed of sound in aluminium is 5100m/s and in brass it is 6,923. So, if the sound wave is moving from aluminum to the brass medium, we can clearly observe that the speed of sound is decreasing. So, we can say here that it decreases.

Therefore, the correct option is B.

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Answer:

Friction

Explanation:

Explanation:

in the first thing we are allowing bacteria to grow

in the second one we are killing it

When an 80 kg man moving at 120.75 m/s pushes a 53 g stone away from him while lying on a surface with little friction, the stone moves at a speed of 4.6 m/s.

Let the man acquire the speed v in the opposite direction.Let the momentum be conserved here.The momentum of the stone before the push is: p₁ = 0The momentum of the stone after the push is: p₂ = m × vWhere m is the mass of the stoneThe impulse is given as: J = p₂ - p₁Now, we know that the impulse (J) = Force (F) × time (t).

We also know that force is mass × acceleration. Therefore, the impulse can be written as: J = m × a × tUsing these equations we can solve for the acceleration (a).a = J/(m × t)Now, the acceleration is the same for the man and the stone, but the masses are different.

Therefore, the man acquires a speed v that is much smaller than the velocity of the stone. Substituting the given values we get,a = (m₂v₂ - m₁v₁)/(m₂t₂)  =  (0.053 × 4.6)/(80 × t) = 0.00109/t m/s². After equating the forces acting on both the stone and the man, we have;Fman = - Fstone.

This is because the man's speed is in the opposite direction to the stone.Let u be the initial speed of the man before he shoves the stone away from himself.

Using the momentum formula, m1u1 + m2u2 = m1v1 + m2v2.The mass of the stone is 0.053 kg while the man's mass is 80 kg.So,80u + 0.053 × 0 = 80v + 0.053 × 4.6v = (80u) / 0.053+4.6v = (80u) / 0.053v = 120.75u.

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The fraction of the total energy is in the form of kinetic energy when the block is at position (x =1/2 A) is 3/4

When the block is at position x=1/2A, its velocity is zero and the total energy is entirely potential energy. At this position, the displacement from equilibrium is half of the amplitude, so x = 1/2 A.

The total energy of the system is given by: E = 1/2 kA², where k is the spring constant and A is the amplitude.

At position x=1/2A, the potential energy is: U = 1/2 k (1/2 A)² = 1/8 kA².

The kinetic energy is equal to the total energy minus the potential energy:

K = E - U = 1/2 kA² - 1/8 kA² = 3/8 kA².

Therefore, the fraction of the total energy in the form of kinetic energy when the block is at position x=1/2A is:

K/E = (3/8 kA²) / (1/2 kA²) = 3/4.

The correct answer is E. 3/4.

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The proportion of pecan trees between 43 and 46 feet tall is 0.1501.

The z-score formula is given by:

z = (x - μ) / σ

Where:

x is the given value (height)

μ is the mean of the distribution (42 feet)

σ is the standard deviation of the distribution (7.5 feet)

For 43 feet:

z(43) = (43 - 42) / 7.5 = 0.1333

For 46 feet:

z(46) = (46 - 42) / 7.5 = 0.5333

Subtracting the smaller value from the larger value gives us the proportion between the two heights.

Using the standard normal distribution table, we find:

P(z < 0.1333) ≈ 0.5530

P(z < 0.5333) ≈ 0.7031

Therefore, the proportion of pecan trees between 43 and 46 feet tall is: 0.7031 - 0.5530 = 0.1501.

Thus, the correct answer is (A) 0.1501.

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Answer:

The substance of the physical world; anything that occupies space or has substance. An organized way of scientists to gather and pursue scientific knowledge. Consists of three main components: Hypothesis, Observation, and Experimentation. One of the main components of the Scientific method.

Explanation:

Answer:

the length of the cannon

the power of the gunpowder

Answer:

i would say B decrease mass of cannon or decrease mass of cannon ball

Explanation:

because when you fire the cannon the cannon ball and powder exit the cannon then that leaves the cannon ball and i would say that the explosion would force it out the cannon but would not increase its mass.

The laser is fired at a diffraction grating with 800 lines per cm, again 2.0 m from the screen behind it. The distance between the slits in the diffraction grating is 1.25 x 10^(-5) meters.

To determine the distance between the slits in the diffraction grating, we need to use the formula:

d = 1 / N,

where d is the distance between the slits and N is the number of lines per unit length on the grating.

Given that the diffraction grating has 800 lines per cm, we can convert it to lines per meter:

N = 800 lines/cm = 800 lines / (0.01 m) = 80000 lines/m.

Now we can substitute this value into the formula to calculate the distance between the slits:

d = 1 / N = 1 / 80000 lines/m = 1.25 x 10^(-5) m.

Therefore, the distance between the slits in the diffraction grating is approximately 1.25 x 10^(-5) meters.

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The answer is 200 joules.

Answer:

Its answer is 200joule.

Explanation:

Hope it's helpful for you

Answer:

Yes

Explanation:

If lamp A burnt out there would still be a wire above it that connects lamp B and C to the power source

Answer: the answer is A, C, E

Explanation:

Time management is apart of your study schedule so you will need to determine when to study, same goes with how to use ur study time, lastly it helps create ur study schedule to help find out what time you are free to study. :)

As you're applying force to the car, the mud which is a sinking surface would but you in the same place as the car is. The car is stuck in the mud and sunk to point where it cannot be pulled out unless an outside force interferes. When you apply force into the car and try to push it out, you would be put in the same situation. You would be experiencing friction which is an opposing force, in this problem, a simple machine such as a pulley would be helpful as it can lift the car from the outside. The car would act as a load and someone or some type of machine can use force to pick the car out of the mud. But if you were to try to push it out of the mud, you would just sink as the force applied would only put you in the same situation as the car, overall resulting in both beings (objects - car, human - "you" POV) being stuck in the same conumdrum.

Answer:

See below

Explanation:

Gravity will pull you down as you stand in the mud.

Additionally , if you do not push exactly horizontally ......like you push UP some , the equal and opposite force will push YOU down into the mud.

  This would be like picking up a weight while you are standing there

      F = ma  will be greater and you will get muddier !

Answer:

The truce ended all wars

Explanation:

The Olympic Truce or the sacred truce, is the declaration made by ambassadors for the laying down of arms and the stop of all hostilities starting from seven days before the  Olympic games began and ending seven days after the games to provide safe passage for travelling athletes and also spectators to and from the Olympic games

However, the  games were held during Persian wars and also during the Peloponnesian wars. As such the truce stopped mainly conflicts that have direct impact on the Olympic games and there was an attack in Olympia in 364 BC during the games.

Answer:

The truce ended all wars

Explanation:

Apex

The characteristics of electrostatics we can find the results for the attraction of the charge by a metal plate are:

        a) The plate has no initial charge.

        b) The plate has an initial charge.

Electrostatics studies the forces between charged particles, finding that charges of the same sign repel and charges of the opposite sign attract.

Materials can be classified according to their charges mobility into two types:

a) Indicate that we bring a charge close to a metal plate and it is attracted.

   Because the plate is metallic, it has mobile charges.

The charge repels the charges of the same sign that are in the vicinity of it and there is a plate a excess of the opposite sign charges, therefore the plate attracts the charge, when removing the charge the plate remains neutral.

Therefore, for the plate to be attracted, it does not necessarily have to be charged.

b) Indicates that the charge is repelled to the metal plate.

This implies that there are excess charges on the plate of the same sign as the charge on the sphere.

When the sphere approaches, it repels charge of the same sign, therefore the charge plate decreases, but for there to be repulsion force the plate must be initially charged.

In conclusion, using the characteristics of electrostatics we can find the results for the attraction of the charge by a metal plate are:

     a) The plate has no initial charge.

     b) The plate has an initial charge.

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Answer:

D. A followed by B

Explanation:

You can see at section A solid Ice at temperature 0°C gets heated up for and all the energy generated from heating up the ice is used to break the bonds which holds the ice together as a solid .

while at Section B the liquid water at 100°C changes to vapor because the heat energy applied here breaks intermolecular bonds c.

The section where A is followed by C of the heating curve illustrate this process. The correct option is D.

The heating curve represents the association between the supply temperature of the heating system and the external air temperature.

As can be seen in section A reliable Ice at 0°C is heated, and all of the energy generated by heating the ice is used to shatter the bonds that hold the ice together as a solid.

While in Section B, liquid water at 100°C transforms to vapor because the heat energy applied here shatters the intermolecular bonds c.

Thus, the correct option is D.

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Answer:

Earthworm lives in the soil, eats the soil which has organic matter such as decaying vegetation or leaves and crawls. While housefly lives in dirty places, feeds on faeces and flies.

Hope I get a brainliest answer.

To calculate the height of the cliff and the time it takes for the rock to reach the ground when thrown straight down, we can use the equations of motion.

(a) Height of the cliff:

When the rock is thrown straight up, it reaches its highest point before falling back down. The time it takes for the rock to reach its highest point is equal to the time it takes for the rock to fall back down to the ground.

Using the equation:

s = ut + (1/2)at^2

Where:

s is the distance traveled (height of the cliff),

u is the initial velocity (8.19 m/s),

t is the time (2.32 s),

a is the acceleration due to gravity (-9.8 m/s^2, taking downward direction as negative).

Rearranging the equation:

s = ut + (1/2)at^2

s = (8.19)(2.32) + (1/2)(-9.8)(2.32)^2

s = 19.004 - 25.798

s = -6.794 m

Since the height of a cliff cannot be negative, we take the absolute value of the result:

Height of the cliff = |s| = 6.794 m

So, the height of the cliff is approximately 6.794 meters.

(b) Time to reach the ground when thrown straight down:

When the rock is thrown straight down with the same speed, the initial velocity (u) is still 8.19 m/s, but the acceleration due to gravity (a) remains -9.8 m/s^2.

Using the equation:

s = ut + (1/2)at^2

Where:

s is the distance traveled (height of the cliff, which is now negative),

u is the initial velocity (8.19 m/s),

t is the time we want to find,

a is the acceleration due to gravity (-9.8 m/s^2, taking downward direction as negative).

Substituting the known values:

-6.794 = (8.19)t + (1/2)(-9.8)t^2

Rearranging the equation:

-6.794 = 8.19t - 4.9t^2

Rearranging further:

4.9t^2 - 8.19t - 6.794 = 0

Solving this quadratic equation, we find two possible values for t: 0.828 seconds and 1.303 seconds. Since we are considering the time it takes to reach the ground, the valid solution is t = 0.828 seconds.

Therefore, when the rock is thrown straight down, it takes approximately 0.828 seconds to reach the ground.

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The new volume of the air sample is approximately 8.71 mL , we can use the combined gas law, which relates the initial and final conditions of temperature, pressure, and volume.

The combined gas law equation is:

(P1 * V1) / (T1) = (P2 * V2) / (T2)

Given:

P1 = 0.875 atm

V1 = 4.00 mL

T1 = 250.5 °C + 273.15 (convert to Kelvin)

P2 = 305 torr (convert to atm)

T2 = 185 °C + 273.15 (convert to Kelvin)

Let's plug in the values and solve for V2:

(P1 * V1) / (T1) = (P2 * V2) / (T2)

(0.875 atm * 4.00 mL) / (250.5 °C + 273.15 K) = (305 torr * V2) / (185 °C + 273.15 K)

Now, let's convert the units to be consistent:

(0.875 atm * 4.00 mL) / (523.65 K) = (0.402 atm * V2) / (458.15 K)

Cross-multiplying:

(0.875 atm * 4.00 mL) * (458.15 K) = (0.402 atm * V2) * (523.65 K)

Simplifying:

3.50 atm·mL·K = 0.402 atm * V2

Dividing both sides by 0.402 atm:

V2 = (3.50 atm·mL·K) / (0.402 atm)

V2 ≈ 8.71 mL

Therefore, the new volume of the air sample is approximately 8.71 mL.

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Answer:

Explanation:

Given:

T = 1/10 s  -  Wave oscillation period

_____________________________

f - ?

The frequency of the wave:

f = 1 / T = 1 / (1/10) = 10 Hz

The process of shaking a sample in a sieve is known as mechanical sieving or dry sieving. This technique is commonly used in geology to separate different-sized particles or grains from a rock sample.

To calculate the projected mass of each rock type after sieving for 24 hours, the following steps can be taken:

The projected mass of each rock type will depend on the initial composition of the rock sample and the size range of each rock type. Granites are typically composed of coarse to medium-grained crystals, while basalts are composed of fine-grained crystals. Marbles are metamorphic rocks composed mainly of calcite or dolomite.

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A thermal energy transfer portfolio would be an excellent way for students to showcase their knowledge and understanding of this important scientific concept.

Thermal energy transfer is the energy transfer between two or more objects that have different temperatures. This energy transfer can take place in three different ways: conduction, convection, and radiation. A portfolio is a collection of documents or pieces of work that demonstrate a person's skills, abilities, and achievements in a particular area.

Therefore, a thermal energy transfer portfolio would be a collection of documents or pieces of work that demonstrate a person's skills, abilities, and achievements related to thermal energy transfer. This portfolio could include lab reports, experimental data, diagrams, and explanations of the various ways thermal energy can be transferred.

For example, a student's thermal energy transfer portfolio might include:

1. A lab report detailing an experiment they conducted to measure the rate of heat transfer through different materials using conduction.

2. A diagram showing the process of heat transfer through convection in a fluid, such as air or water.

3. A written explanation of the concept of radiation and how it relates to thermal energy transfer.

4. A spreadsheet of data showing the temperature changes in a system as heat is transferred through it.

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The correct answer is the upward buoyant force on an object immersed in water (or other fluid) is equal to the weight of the fluid displaced by the object.

Buoyancy refers to the capacity of a fluid, particularly a liquid, to support a body floating or partially submerged in it. It’s an upward force that works against gravity, making things float.

It is the reason boats, logs, and beach balls float on the water's surface. The buoyant force is equal to the weight of the fluid displaced by the object, according to Archimedes' principle.The weight of the displaced fluid is equal to the weight of the object that is entirely submerged in the fluid. Furthermore, this buoyant force is equal to the force exerted on the object by the fluid in which it is submerged. An object that is more dense than the fluid in which it is submerged would sink, while an object that is less dense than the fluid in which it is submerged would float. The amount of buoyant force generated on a submerged or floating object is determined by the volume of the fluid displaced by the object, as the buoyant force is proportional to the displaced fluid's volume. Therefore, the answer to the previous question indicates that the upward buoyant force on an object immersed in water (or other fluid) is equal to the weight of the fluid displaced by the object.

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The final speed of the bike is 5 m/s.

Speed is  measured as the ratio of distance to the time in which the distance was covered.

To calculate the final velocity, we use the formula below.

Formula:

v = u+at................ Equation 1

Where:

From the question,

Given:

Substitute these values into equation 1

Hence, the final speed of the bike is 5 m/s.

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Answer:

Explanation:

Initial velocity , u = 27 m/s

displacement before stop,  s = 41.5 m .

final velocity,  v = 0

acceleration a = ?

v² = u² + 2 a s

0 = 27² + 2 x a x 41.5

a = - 27² / 2 x 41.5

= - 8.78 m /s

If pressure has to be decreased the height of the piston needs to be increased which will increase volume of gas eventually decreasing the pressure.

The thrust (perpendicular force on a surface) acting per unit area of a body is referred to as pressure. It can be stated mathematically as follows: Pascal is the SI unit of pressure (Pa). One Pascal is the amount of pressure one Newton of force applies to a square inch of space. Additionally, 1 P a = 1 N / m 2. In the International System of Units, pressure or stress is measured in pascals (Pa) (SI). It bears Blaise Pascal's name, a mathematician and physicist. Applied force of one newton (N) per square metre is equal to one pascal (P) (m2).

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Travels in longitudinal waves

Travels most slowly through a gas

Speeds up when temperature is increased

Is caused by vibration

Explanation for correct answers:

Yes, it does travel in longitudinal waves

Yes, sounds weird, but travels faster in the water

Yes, does speed up when temperature is increased

And yes, Is caused by vibration.

Can travel through a vacuum

Explanation for wrong answer:

actually, in space, there is NO sound, because there are no particals for the sound to vibrate with, there's just empty SPACE.

Answer:

A theory is an opinion but in fancy format.

Explanation:

it is an explanation of observed regularities. The terms "established" and "observed regularities" are important here.

A theory is a way to explain a opinion on a certain topic.