Question #18:

A steam engine (assume a Carnot engine) has an efficiency of 34.8%. If the waste heat has a temperature of 76 °C, what is the temperature of the boiler? Answer in units of °C.

Answer:

See below

Explanation:

KE = 1/2 m v ^2

    = 1/2 (250/1000) 300^2   j         the bullet is 250/1000  kg  ( assuming g is grams and not GRAINS - in which bullet weight is usually measured)

force to stop it is the same number

PE = mgh = .5 *9.81  *  .75 =

     doubling height will double PE

2 x 10^6  =  40 * 9.81  *  h      sove for 'h' in meters  

Initial kinetic energy is 11250 J and magnitude of force to stop bullet is 75 N.

The GPE for 0.75m height floor is 3.75J.

The GPE for double of 0.75m height is 7.5J.

The high on which 40 kg mass is lifted is 5000m.

The kinetic energy of an object is the energy that it possesses due to its motion.

[tex]KE = 1/2 m v ^2[/tex]

      [tex]=1/2 (250/1000) 300^2 J\\= 11250 J[/tex]

Work done,

[tex]W= fs\\\\f=\frac{W}{s}\\\\f=\frac{11250}{150}[/tex]

[tex]f=75 N[/tex]

Gravitational potential energy is the potential energy a massive object has in relation to another massive object due to gravity.

PE = mgh

    = .5 *9.81  *  .75

    = 3.75 J

Potential energy when height doubles = 7.5J

The potential energy is given by

[tex]PE = mgh\\\\h = PE/ mg\\\\h = 2*10^6 J /40*9.8\\\\h = 5000 m[/tex]

To learn more about Kinetic and potential energy here

https://brainly.com/question/15764612

#SPJ2

Answer:

B. has the greatest mass

Explanation:

mass & distance affect pull

grativy affects speed & shape of orbit of the planet

quiziz

Answer:

1 / f = 1 / i + 1 / o             1 / f = (o + i) / i o

f = i o / (o + i)

f = -26.5 * 8.25 / (8.25 - 26.8)

f = -221 / -.308 = 11.8 cm

The sound intensity level of 100 physics professors talking simultaneously is equal to 72 decibel.

Given the following data:

Sound intensity can be defined as a measure of the power of a sound wave per unit area. Thus, sound intensity is a quantity that can be used to measure the energy of sound and its unit of measurement is Watts per square meter.

Mathematically, sound intensity level is given by this formula:

[tex]\beta = 10 log(\frac{I}{I_{ref}} )[/tex]

Note: The reference value of sound intensity is equal to [tex]1.0 \times 10^{-12}\;W/m^2[/tex]

Thus, the sound intensity for one (1) professor is given by:

[tex]I_1 = 1.0 \times 10^{-12} \times 10^{5.2}\\\\I_1=1.585 \times 10^{-7}\;W/m^2[/tex]

For 100 professors, the sound intensity is:

[tex]I_{100} = 1.585 \times 10^{-7} \times 100\\\\I_{100}=1.585 \times 10^{-5}\;W/m^2[/tex]

Substituting the parameters into the formula, we have;

[tex]\beta = 10 log(\frac{1.585 \times 10^{-5}}{1.0 \times 10^{-12}})\\\\\beta = 10 log(15.58 \times 10^{6})\\\\\beta = 10 \times 7.2\\\\\beta =72\;dB[/tex]

Read more on sound intensity here: https://brainly.com/question/17062836

Complete Question:

One physics professor talking produces a sound intensity level of 52 dB. It's a frightening idea, but what would be the sound intensity level of 100 physics professors talking simultaneously?

Answer:

72dB

Explanation:

The sound intensity level of one prof is given, that's your β1 (which is equal to 52dB).

Using the sound intensity level formula:

β1= 10log ([tex]\frac{I}{I_{o} }[/tex]) = 52 dB

*This will be useful later on [even if β1 is known]

Set up the formula for β2 (β2 is going to be the new sound intensity, the one for the 100 profs):

β2 = 10 log( [tex]\frac{ 100 I}{I_{o} }[/tex] )

*You need to multiply the intensity of one professor by 100 (because now there's more)

*do some algebra- pull out the 100

β2  = 10 log (100 [tex]\frac{I}{I_{o} }[/tex])

*use log laws

β2 = 10 ( log(100) + log ([tex]\frac{I}{I_{o} }[/tex]) )

*Now, isn't there a familiar part? Well, yes! The expression for β1!

β2 = 10log(100) + β1

β2 = 10log(100) + 52dB

*use your calculator

β2 = 73dB

^^^ that's your new sound intensity level

Blood travels through the body in tubes called arteries and veins.

Blood vessels are tubes through which the blood circulates in the body. Blood vessels include the following;

Thus, we can conclude that blood travels through the body in tubes called arteries and veins.

Learn more about blood vessels here: https://brainly.com/question/25149738

#SPJ1

Answer:

B) sublimation

Explanation:

An example is the vaporization of frozen carbon dioxide (dry ice) at ordinary atmospheric pressure and temperature.

Answer:

sublimation

Explanation:

sublimation, in physics, conversion of a substance from the solid to the gaseous state without its becoming liquid. An example is the vaporization of frozen carbon dioxide or dry ice(CO2)

or Solid Chlorine (Cl2) at ordinary atmospheric pressure and temperature. The phenomenon is the result of vapour pressure and

temperature relationships.

Please Mark me Brainiest

Answer:

200 Nm

Explanation:

Work Done by Particular Force = Particular Force × Distance

Answer:

When oil is spilled in the sea it will normally break up and be dissipated or scattered into the marine environment over time. This dissipation is a result of a number of chemical and physical processes that change the compounds that make up oil when it is spilled. The processes are collectively known as weathering.

Hope This It What You Wanted :)

Answer:

The correct answer is C

Explanation:

Hope this helped :)

if im wrong pls tell me.

Answer:

Speed Formula:

[tex]s = \frac{d}{t} [/tex]

Answer:

An induced magnetic field is always opposed to the change that produced the magnetic field.

Thus, such a bar magnet will be slowed on its descent thru the pipe because it will produce a current in the pipe that will produce a magnetic field in an opposite direction to the field that produced the current.

(a repelling magnetic field will produce a force that opposes the force producing it - otherwise one has a way to produce pertpetual motion)

Explanation: a reduction in genetic diversity and discomfort for animals that have very exaggerated characteristics.

Answer:

Thermal Energy

Explanation:

When friction acts between two surfaces that are moving over each other, some kinetic energy is transformed into heat energy. Otherwise known as thermal energy.

Answer:

D -- 12

Explanation:

Hope this helps! Please let me know if you need more help or think my answer is incorrect. Brainliest would be MUCH appreciated. Also remember to rate answers to help other students, While leaving thanks to answers that help you. Have a great day!

Answer:

S = v0 t + 1/2 a t^2       a = 0 seems given in the problem

Vp  t = Vr t + 16

both travel for time t but the police car is going faster and travels 16 km farther

t (Vp - Vr) = 16

t = 16 km / (100 - 80) km/hr

t = 16 / 20 hr = 4/5 hr = 48 min

Answer:

W=Fd

This is the equation for it

Answer:

D.

Explanation:

The answer should be D. because if it increases by a factor of 2 then it will decrease at a factor of 4.

I hope it helps! Have a great day!

Anygays-

Answer:

weight = 30000 Newton

Given:

========================

[tex]\sf pressure \ (Pa)=\dfrac{force \ (N)}{area \ (m^2)}[/tex]

[tex]\dashrightarrow \sf \ 60 000 = \dfrac{force}{0.5}[/tex]

[tex]\dashrightarrow \sf \ force =60 000 *0.5[/tex]

[tex]\dashrightarrow \sf \ force =30000 \ N[/tex]

========================

Weight is the force due to gravity.

Thus, force = gravity = 30000 N

Answer:

36.04N

Explanation:

accelerating force: mass × acceleration

F=ma

m=212/10= 21.2kg

a=1.7m/s2

F=21.2×1.7

=36.04N

Answer:

It is called Motion Energy

Explanation:

Answer:

amount and speed of traffic on the acceleration lane and expressway.

Answer: i would say true uwu

Explanation:hope this helps!

  ....Max-

Answer:

[tex]40h[/tex]

Explanation:

Use the velocity formula to solve

[tex]v = \frac{d}{t}[/tex]

In this question, you are given velocity [tex]v = 45km/h[/tex], and you are given a distance, [tex]d = 1800km[/tex].  Time in this question is what you'll need to find.

Start by rearranging the velocity formula, to isolate for t.

[tex]v = \frac{d}{t}[/tex]

Start by multiplying both sides by t

[tex]v(t) = \frac{d}{t}(t)\\\\vt = d[/tex]

Then divide both sides by v.

[tex]vt\frac{1}{v} = d/v\\ \\t = \frac{d}{v}[/tex]

Now that you've isolated for time, sub in your values and calculate.

[tex]t = \frac{d}{v} = \frac{1800km}{45km/h} = 40 h[/tex]

Answer:

The first reactant is methane, the next is oxygen, the first product is carbon dioxide and the second product is water.

The word equation is:

methane + oxygen → carbon dioxide + water

The balanced symbol equation is:

CH₄ + 2O₂ → CO₂ + 2H₂O

Explanation:

In any combustion reaction, fuel is burned in the presence of oxygen to produce carbon dioxide and water.

An equation is balanced when there are the same number of atoms of each element on both sides of the arrow.

Hope this helps!

 The work done on the car due to friction is -125 J.

Work is said to be done when a force moves an object through a certain distance.

To calculate the workdone on the car by friction, we use the formula below

Formula:

Where:

From the question,

Given:

Substitute these values into equation 1

Hence, The work done on the car due to friction is -125 J.

Learn more about work done here: https://brainly.com/question/21854305

Answer:

W = 1/2 x P x E

Explanation:

Let :

Formula

Solving

Let's see

[tex]\\ \rm\rightarrowtail W=P\vec{E}(cos\theta_i-cos\theta_f)[/tex][tex]\\ \rm\rightarrowtail W=P\vec{E}(cos0-cos60)[/tex]

[tex]\\ \rm\rightarrowtail W=P\vec{E}(1-1/2)[/tex]

[tex]\\ \rm\rightarrowtail W=\dfrac{P\vec{E}}{2}[/tex]

(1) The thermal energy absorbed by the Carnot engine is 7.15 x 10⁸ J.

(2) The thermal energy lost per hour by the Carnot engine is 2.75 x 10⁸ J.

The thermal energy absorbed by the heat engine is calculated as follows;

[tex]Q_h = \frac{P\Delta t}{1 - T_c/T_h}[/tex]

where;

[tex]Q_h = \frac{(122,000) \times (3600)}{1 - \frac{282}{731} } \\\\Q_h = 7.15\times 10^8 \ J[/tex]

The thermal energy lost per hour by the heat engine is calculated as follows;

[tex]Q_c = Q_h - P\Delta t\\\\Q_c = (7.15 \times 10^8 )\ - \ (122,000 \times 3600)\\\\Q_c = 2.75 \times 10^8 \ J[/tex]

Learn more about heat lost by Carnot engine here: https://brainly.com/question/25819144

Answer:

Explanation:

Answer:

yes

Explanation:

as speed is a scalar quantity and velocity is a vector quantity. Which means speed only depends on the magnitude at which it travels but velocity depends on the speed at which travel and also the direction to where the object travels.

pls mark as brainliest