1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Rzqust [24]
3 years ago
13

An energy-efficient water heater draws 4 amps in a 220-volt circuit. It costs $75 more that a standard water heater that draws 1

8 amps in a standard 115-volt circuit. If electricity costs 10 cents per kilowatt-hour, how long would you have to run the efficient water heater to recoup the difference in price? Show your calculations.
Physics
1 answer:
HACTEHA [7]3 years ago
3 0
The answer to the question above is "630.25 hours" which is the time to recoup the difference in the water heater cost. This problem can be solved using a simple algebra equation which stated as (18*115*0.1/1000)x - (4*220*0.1/1000)x = $75. In this formula, x represents the time to recoup the difference in the water heater cost (Calculation: 0.207x-0.088x=75 --> 0.119x = 75 --> x = 630.25)<span>. </span>
You might be interested in
What is the force of a ball if it has a mass of 10 kg and accelerates at an acceleration of 20 m/s^2? *
vampirchik [111]

Answer:

200N

Explanation:

mass(m) = 10 kg

acceleration(a) = 20 m/s^2

Force = mass * acceleration

          = 10*20

          = 200 N

Force = 200N

4 0
2 years ago
a fan acquires a speed of 180 rpm in 4s, starting from rest. calculate the speed of the fan at the end of the 5th second startin
KengaRu [80]

Answer:

225 rpm

Explanation:

The angular acceleration of the fan is given by:

\alpha = \frac{\omega_f - \omega_i}{\Delta t}

where

\omega_f is the final angular speed

\omega_i is the initial angular speed

\Delta t is the time interval

For the fan in this problem,

\omega_i = 0\\\omega_f = 180 rpm\\\Delta t=4 s

Substituting,

\alpha = \frac{180-0}{4}=45 rpm/s

Now we can find the angular speed of the fan at the end of the 5th second, so after t = 5 s. It is given by:

\omega' = \omega_i + \alpha t

where

\omega_i = 0\\\alpha = 45 rpm/s\\t = 5 s

Substituting,

\omega' = 0 + (45)(5)=225 rpm

7 0
2 years ago
Please Help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
arsen [322]

Answer:

Given that

speed u=4*10^6 m/s

electric field E=4*10^3 N/c

distance b/w the plates d=2 cm

basing on the concept of the electrostatices

now we find the acceleration b/w the plates  to find the horizontal distance traveled by the electron when it hits the plate.

acceleration a=qE/m=1.6*10^{-19}*4*10^3/9.1*10^{-31} =0.7*10^{15}=7*10^{14} m/s

now we find the horizontal distance traveled by electrons hit the plates

horizontal distance

X=u[2y/a]^{1/2}

=4*10^6[2*2*10^{-2}/7*10^{14}]^{1/2}

=3*10^{-2}= 3 cm

5 0
3 years ago
The earth and the moon exert forces on each other which forces is greater? explain
Helen [10]

Thank you for your question, what you say is true, the gravitational force exerted by the Earth on the Moon has to be equal to the centripetal force.

An interesting application of this principle is that it allows you to determine a relation between the period of an orbit and its size. Let us assume for simplicity the Moon's orbit as circular (it is not, but this is a good approximation for our purposes).

The gravitational acceleration that the Moon experience due to the gravitational attraction from the Earth is given by:

ag=G(MEarth+MMoon)/r2

Where G is the gravitational constant, M stands for mass, and r is the radius of the orbit. The centripetal acceleration is given by:

acentr=(4 pi2 r)/T2

Where T is the period. Since the two accelerations have to be equal, we obtain:

(4 pi2 r) /T2=G(MEarth+MMoon)/r2

Which implies:

r3/T2=G(MEarth+MMoon)/4 pi2=const.

This is the so-called third Kepler law, that states that the cube of the radius of the orbit is proportional to the square of the period.

This has interesting applications. In the Solar System, for example, if you know the period and the radius of one planet orbit, by knowing another planet's period you can determine its orbit radius. I hope that this answers your question.


8 0
3 years ago
Approximately how many news cases of STIs occur in the United States
galben [10]

<u>Approximately 20 million new cases of STIs occur every year in United</u> <u>States.Half of the new cases occur in young people aged between 15–24. </u>

Though younger people are accountable for nearly half of new cases, a recently taken study showed that last year, only around 12% underwent the test for STIs. Center for Disease Control and Prevention (CDC) estimates that each year, undiagnosed STIs causes 24,000 women to become infertile.

Sexually transmitted infections (STIs) are a substantial health challenge which the United States is facing. A very Strong public health awareness and infrastructure is crucial to prevent and control STIs, especially among the younger generation.

4 0
3 years ago
Other questions:
  • What is a <br> quadratic graph
    6·1 answer
  • In order to use the Pythagorean theorem to find the magnitude of a resultant vector, which must be true regarding the two initia
    5·1 answer
  • You are watching people practicing archery when you wonder how fast an arrow is shot from a bow. With a flash of insight you rem
    11·1 answer
  • If a train travels at a constant 18.0 m/s, how far would it move in one hour? In 1.00 minute? In 1.00 second?
    11·1 answer
  • Name three different units of energy used to measure heat and describe what type of situations each is usually used.
    13·1 answer
  • Which statements about electric field lines are correct? Check all that apply.
    15·1 answer
  • I am having trouble with writing a 2 paragraph summary about this vidio can someone help me
    5·1 answer
  • If an object is moving and the forces acting on it are unbalanced in the direction of motion, the object will...
    5·2 answers
  • When will the human population stop growing?
    14·2 answers
  • Most towns use a water tower to store water and provide pressure in the pipes that deliver water to customers. The figure below
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!