An object accelerates to a velocity of 230 m/s over a time of 2.5 s. The acceleration it experienced was 42 m/s2. What was its initial velocity?

Answer:

The final temperature is 31.94°

Explanation:

The mass of the water in the container m₁ = 200 g = 0.2 kg

The initial temperature of the water,  T₁₁ = 30°C

The mass of the iron, m₂ = 200 g = 0.2 kg

The temperature of the iron T₂₁= 50°C is immersed in the water,

The specific heat capacity of the water, c₁ = 4200 J/(kg·°C)

The specific heat capacity of the iron, c₂ = 450 J/(kg·°C)

Heat capacity relation is given by the formula;

Heat capacity Q = Mass, m × Specific heat capacity, c × Temperature change, (T₂ - T₁)

Given that energy can neither be created nor destroyed, and with the assumption that all the heat lost by the nail is gained by the water we have;

Heat lost by iron nail = Heat gained by the  water

m₁ × c₁ × (T₂ - T₁₁) = m₂ × c₂ × (T₂₁ - T₂)

Where, T₂ is the final temperature

0.2 kg × 4200 J/(kg·°C) × (T₂ - 30) = 0.2 kg × 450 J/(kg·°C) × (50° - T₂)

840·T₂ - 25200 = 4500 - 90·T₂

4500 + 25200 = 840·T₂ + 90·T₂

29700 = 930·T₂

T₂ = 29700/930 = 31.94°.

The final temperature = 31.94°.

Answer:

The answer is B, true.

Because same current flows through each resistors in Series.

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[tex] \LARGE{ \underline{ \tt{ \pink{True \: or \: False}}}}[/tex]

The above statement is true.

❍ In series combination of resistors, the total electric current is equal to the current flowing through each resistor..

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Answer:

17.15 m

Explanation:

Assuming the well is empty (full of air instead of water), the speed of sound is v = 343 m/s.

The water well acts as a pipe closed at one end.  Therefore, the depth of the water well must be an odd multiple of a quarter of the resonant wavelength.

L = (2n − 1) λ/4, n = 1, 2, 3, etc.

v = λf, so λ = v/f.  Substituting:

L = (2n − 1) v/(4f)

Solving for frequency:

f = (2n − 1) v/(4L)

The difference between two successive resonant frequencies is therefore:

Δf = (2(n+1) − 1) v/(4L) − (2n − 1) v/(4L)

Δf = (2n + 1) v/(4L) − (2n − 1) v/(4L)

Δf = 2 v/(4L)

Δf = v/(2L)

Plugging in values:

50 Hz − 40 Hz = 343 m/s / (2L)

2L = 34.3 m

L = 17.15 m

Answer:

A gas usually has much lower density than a solid or liquid. ... The molecules or atoms in a gas are much further apart than in a solid or a liquid. Gas molecules or atoms are usually flying around at very high speeds, occasionally bouncing off each other or the walls of the container the gas is in.

Answer:

Since N/m is the unit of spring constant N/nm would be the possible unit for a spring constant.

A. N/nm is the possible unit for a spring constant.

The units at the spring regular are Newton/meter (N/m). The poor signal within the above equation is an indication that the direction that the spring stretches is opposite the path of the pressure that the spring exerts.

Because the force is measured in Newtons and the spring consistent is multiplied with the aid of the gap in meters, the spring constant need to have devices that get rid of meters, ensuing most effective force. The most effective devices that work for the spring regular are for that reason, Newtons in step with the meter.

Learn more about spring constant here: https://brainly.com/question/1968517

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Oil is optically denser than water. When sound/light goes from optically denser medium to optically rarer medium, their velocity increase and they moves away for normal.

The sound wave speeds up and bends

[tex] \Large{ \underline{ \boxed{ \pink{ \bf{Option \: (D)}}}}}[/tex]

As, In optics we learnt that light undergoes refraction when travels from medium of different densities. Similarly, Sound also follows the law of refraction.

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Answer:

the sound wave slows down and bends

Explanation:

a p e x

Answer:

Distance : 0.06533 meters or 65.33 mm

Explanation:

To solve this problem we can make the forces equal when the system is at equilibrium.

mass [tex]*[/tex] gravity ( constant ) = spring constant

where l = the length at which the rubber band is stretched

0.2 kg [tex]*[/tex] 9.8 m / s² = 30 N/m

1.96 kg [tex]*[/tex] m / s² = 30 N/m

l = 1.96 kg [tex]*[/tex] m / s² / 30 N/m = 0.06533 meters / 65.33 mm

The rubber band is stretched a distance of 0.06533 meters, or 65.33 mm.

Answer:

0.065

Explanation:

Apex i just got it right

Answer: D

Explanation:

Given that a car travels from point A to B in 3 hours and returns back to point A in 5 hours. Points A and B are 150 miles apart along a straight highway.

From point A to B

The speed = distance / time

Where

Distance = 150 mile

Time = 3 hours

Substitute the values into the formula

Speed = 150/3 = 50 mile/ hours

From Point B to Point A

Distance = 150 miles

Time = 5 hours

Where speed = distance/ time

substitute all the parameters into the formula

Speed = 150/5 = 30 mph

Therefore, The car travels at 50 mph for the first half and 30 mph for the second half.

The correct answer is option D

Answer:

Explanation:it is too easy

Answer:

Explanation:

In all works of life science can be applied, in-fact science has already been applied already, even in the humanities, social sciences and art related studies sciences is being applied,

    Furthermore, the application of science and technology knows no boundaries, and as science is advancing day by day, expanding to new frontiers and breaking new limits so is it application to all works of life and relevance everyday.

Answer:

The correct option is;

D: Its vibrations are not transmitted to the moon's atmosphere

Explanation:

A tuning fork is used to produce sound by vibration  such that the tune produced is pure

The tune, sound, produced by the tuning fork is transmitted as sound wave through the air by means of the gases of the air as a transmission medium so people at a distance that have air around them can hear the tuning fork sound

On the Moon's surface, the atmosphere is very and it is referred to technically as an exosphere, so the sound of the tuning fork has no medium through which to transmit and therefore, it is not transmitted on the Moon's atmosphere.

Answer:

Hey there!

Mixtures are physically combined and can be separated. For example, sand and water is a mixture.

Pure substances are samples of matter with definite, and unchangeable chemical properties. For example, diamond is a pure substance.

Let me know if this helps :)

a pure substance is a substance that has not been mixed with anything, a mixture has been mixed with another substance. an example is

dirt +water=mud iron is an example of a substance

Answer:

66.86m

Explanation:

Velocity of ball thrown, u = 23.5 m/s

Initial height of the ball above the water, H = 11.5 m

Angle of projection, θ = 39.5°

Vertical components of veloclty = usinθ

Horizontal components of veloclty = ucosθ

The soft ball hits the water after time 't'

Considering the second equation of motion

S = ut + 1/2at^2........ 1

But since the ball went through motion under gravity ( free fall ) rather than linear motion, then equation 1 can be rewritten as:

H = ut +/- 1/2gt^2

H = - 11.5m

U = usinθ

θ = 39.5°

a = -g = -9.8m/s^2

- 11.5m = 23.5(sin39.5°)t + 1/2(-9.8)t^2

-11.5m = 23.5(0.6360)t - 4.9t^2

-11.5m = 14.946t - 4.9t^2

4.9t^2 -14.946t-11.5m = 0

Since the ball drifted horizontally

D = (Ucosθ)t

Where θ = 39.5°

U = 23.5m/s t=

Alternatively,

horizontal component of the velocity is 23.5 cos 39.5º = 18.1331 m/s

now how long does it take the ball to raise to a peak and fall to the water.

vertical component of velocity = 23.5 sin 39.5º = 14.947m/s

time to reach peak t = v/g = 11.947/9.8 = 1.5252 sec

peak reached above cliff top is

h = ½gt² = ½(9.8)(1.5252)²

= ½×22.797

= 11.3985m

now the ball has to fall 11.3985+ 11.5 = 22.8985m

time to fall from that height is

t = √(2h/g) = √(2• 22.8986/9.8) = 2.1617 sec

add up the two times to get time it is in the air, 2.1617 + 1.5252 = 3.6869

now haw far does the ball travel horizontally in that time

d = vt = 18.1331 ×3.6869= 66.856m

= 66.86m

Answer:

Emphasizes

Explanation:

The expression of an art is intelligible to those that understand it, as such to make an impression an artist has to emphasize the point they want to communicate

An art is an expression of the personal experiences of the artist or a reaction to events or to reveal the realities as seen by the artist such as global warming and the environment, so as to get the attention of people with the goal to change them, such that a good art changes the most people, hence the need for emphasis.

Answer:

A - emphasizes

Answer:

Explanation:

The speed of sound is very high . It is about 340 m /s . In one echo , it takes approximately

2 x 100 / 340

= .6 sec

In 10 simultaneous echo , it will take 6 s . It is difficult to measure .6 sec but to measure 6 s is easy and it can be made with greater precision , so we can calculate velocity of sound with great precision .

This is the reason why , instead of one echo , 10 echos are made and duration of 10 echo is measured , rather than making one echo and measuring time of one echo .  

Answer:  A Battery contains chemical energy which transfers electrical energy into the phone, powering it and also transferring Light energy, Sound energy and Heat energy.

Explanation:

If you are talking about mecury as in a chemical element than it is: Hg

If you are talking about the planet Mercury than: The symbol for Mercury represents the head and winged cap of Mercury, god of commerce and communication, surmounting his caduceus (staff). The symbol for Venus is designated as the female symbol, thought to be the stylized representation of the hand mirror of this goddess of love.

Answer:

The symbol of mercury is....

Hydrargyrum ( Hg )

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Answer:

The volume of the cylinder is [tex]653.71\ \text{cm}^3[/tex]

Explanation:

Given that,

The height of the cylinder is 13 cm

Radius of the cylinder is 4 cm

We need to find the volume of the cylinder. The formula that is used to find the volume of a cylinder is given by :

[tex]V=\pi r^2 h\\\\V=\dfrac{22}{7} \times (4)^2 \times 13\\\\V=653.71\ \text{cm}^3[/tex]

So, the volume of the cylinder is [tex]653.71\ \text{cm}^3[/tex]

Answer:

653.45 is the answer

Explanation:

Answer:

The nail exerts an equal force on the hammer in the opposite direction.

Explanation:

The Newtons third law states that there is an equal an opposite reaction for every action. When hammer pushes the nail, the nail will push the hammer back in opposite direction. When the hammer hits a nail then nail will exert the equal and opposite force to the hammer. These both objects will exert force on each other in opposite directions.

Hello, I am BrotherEye

Answer:

Answers are

1. "The nail exerts an equal force on the hammer in the opposite direction."

2. "500 N"

3. "The iron piece exerts a force of 1 N on the magnet in the opposite direction."

4. "When mass moves closer to the point of rotation, rotational inertia decreases."

5. "The skater spins slower because his rotational inertia has increased."

Explanation:

Answer:

The percentage error in quantity P is 19%.

Explanation:

It is given that,

A physical quantity P is related to four observables a, b and c as follows:

[tex]P=\dfrac{a^3b^2}{c^4}[/tex]

The percentage errors of measurements in a, b and c are 1%, 4% and 2% respectively.

We need to find the percentage error in quantity P. It is given by :

[tex]\dfrac{\Delta P}{P}\times 100=(3\times \dfrac{\Delta a}{a}+2\times \dfrac{\Delta b}{b}+4\times \dfrac{\Delta c}{c})\\\\=3\times 1+2\times 4+4\times 2\\\\\dfrac{\Delta P}{P}\times 100=19\%[/tex]

So, the percentage error in quantity P is 19%.

Answer:

True

Explanation:

This is in fact what the Archimedes principle states, and what he used in the famous anecdote about finding if  the crown of the King was really made of gold.

Answer and Explanation:

Data provided in the question

Force = 50N

Length = 5mm

diameter = 2.0m = [tex]2\times 10^{-3}[/tex]

Extended by = 0.25mm = [tex]0.25\times 10^{-3}[/tex]

Based on the above information, the calculation is as follows

a. The Stress of the wire is

[tex]= \frac{force\ applied}{area\ of \ circle}[/tex]

here area of circle = perpendicular to the are i.e cross-sectional  i.e

= [tex]\frac{\pi d^{2}}{4}[/tex]

= [tex]\frac{\pi(2\times 10^{-3})^2}{4}[/tex]

Now place these above values to the above formula

[tex]= \frac{4\times 50}{\pi\times 4 \times 10^{-6}} \\\\ = \frac{50}{\pi}[/tex]

= 15.92 MPa

As 1Pa = 1 by N m^2

So,

MPa = 10^6 N m^2

b. Now the strain of the wire is

[tex]= \frac{Change\ in\ length}{initial\ length} \\\\ = \frac{0.25\times 10^{-3}}{5}[/tex]

= [tex]5 \times 10^{-5}[/tex]

Answer:

Hay diversas leyes que podemos usar acá.

Acá sabemos que la vejiga aumenta su tamaño al reducir la presión, esto tiene sentido, pues al haber menos presión, hay menos fuerza que comprime la vejiga, lo que le permite aumentar su volumen.

Acá tenemos una relación inversa de la forma: V = K/P

Una relación inversa donde la presión esta en el denominador y K es un termino que no depende ni del volumen ni de la presión.

Entonces, a medida que aumenta P, el denominador aumenta, por lo que el valor del volumen decrece.

Un ejemplo de una ecuación similar es la del gas ideal, por ejemplo, para un gas ideal dentro de un globo de volumen V para una dada presión P:

V = nRT/P

donde n es el numero de moles, R es la constante termodinámica y T es la temperatura, acá podemos ver que esta ecuación tiene la misma forma fundamental que la escrita arriba.

Answer:

1. direction of propagation of sound

2.medium through which sound trsnsmitted

Answer:

the force applied to restore a spring to its original length

Explanation:

Answer:

1) The density of the object = 2500 kg/m³

2) The density of the oil = 1250 kg/m³

Explanation:

1) The information relating to the question are;

The mass of the object in air = 0.250 kgf

The mass of the object in water = 0.150 kgf

The mass of the object in the oil  = 0.125 kgf

By Archimedes's principle, we have;

The upthrust on the object in water = Mass in air - mass in water = The weight of the water displaced

The upthrust on the object in water = 0.250 - 0.150 = 0.1 kgf

∴ The weight of the water displaced = 0.1 kgf

Given that the object is completely immersed in the water, we have;

The volume of the water displaced = The volume of the object

The volume of 0.1 kg of water water displaced = Mass of the water/(Density of water)

The volume of 0.1 kg of water = 0.1/1000 = 0.0001 m³

The density of the object = (Mass in air)/ volume = 0.250/0.0001 = 2500 kg/m³

The density of the object = 2500 kg/m³

2) Whereby the mass of the object in the oil = 0.125 kgf

The upthrust of the oil = The weight of the oil displaced

The upthrust of the oil on the object = Mass of the object in air - mass of the object in the oil

The upthrust of the oil on the object = 0.250 - 0.125 = 0.125 kgf

The weight of the oil displaced = The upthrust of the oil

Given that the volume of the oil displaced = The volume of the oil, we have;

The volume of the oil displaced = 0.0001 m³

The mass of the 0.0001 m³ = 0.125 kg

Therefore the density of the oil = 0.125/0.0001 = 1250 kg/m³.

The density of the oil = 1250 kg/m³.

Answer:

The correct option is;

The proposal is denied, because participants will likely suffer psychological harm

Explanation:

Among the recommendations in the report on ethical research with children, it is suggested that the following should be observed by researchers;

1) Seeking consent should be a continuous process

2) Contemplate payment forms other than money to allow more discretion on child safety

3) Have two way communication with the child

4) Ask for assent of the child participating in the research

The above APA suggestions where not met by the researcher in the study.

Answer:

The proposal is denied, because participants will likely suffer psychological harm.

Explanation:

This proposal would cause psychological harm to its participents.

I also took the test and that was the correct answer.

Explanation:

Assuming the 10 m distance is the vertical displacement, the work done by both people is the same.

Work = force × distance

W = (250 N) (10 m)

W = 2500 J

The power of the first person is:

Power = work / time

P = 2500 J / 120 s

P = 20.83 W

The power of the second person is:

P = 2500 J / 60 s

P = 41.67 W

Answer:

1000meters

Explanation:

Let the wavelength of the radio wave be W and it's frequency be f. If the wavelength of a radio wave varies inversely as its frequency, then W∝1/f

W = k/f where k is the constant of proportionality.

k = Wf

If a wave with a frequency of 1800 kilohertz has a length of 200 meters, then k = 1800×200

k = 360,000kHzm

To get the length of a wave with a frequency of 360 kilohertz, we will substitute the value of k and f = 360kHz into the initial formula i.e

W = k/f

W = 360,000/360

W = 1000meters

Hence the length of a wave with a frequency of 360 kilohertz is 1000meters