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
vovangra [49]
3 years ago
12

A fan that is switched on for 1 minute uses 500 W usefully but also wastes 300 W through the emission of sound and heat. What's

the efficiency of the fan?
Physics
1 answer:
koban [17]3 years ago
6 0

Explanation:

Efficiency is defined as the ratio between the useful output over the total amount consumed. E = \frac{useful}{total}

The fan does 500W of useful work while wasting 300 W. The total power consumption is 800 W (500 + 300).

You might be interested in
U are asked to measure the amount of liquid held in a sports drink bottle.which is an appropriate unit of measurement? is grams,
saul85 [17]
Milliliters would be used to find the volume AKA amount of liquid
5 0
3 years ago
A car is moving with a constant velocity of 25 m/s. Which of the following is true?
S_A_V [24]

b) the net force on the car is zero.

Explanation:

Let's analyze each option one by one:

a) the force from the engine is greater than all the forces of friction.  --> FALSE. In fact, the car is moving at constant velocity: this means that its acceleration is zero,

a = 0

and so Newton's second law becomes

\sum F = ma = 0

where \sum F is the net force on the car and m is its mass. This means that the net force on the car is zero: so, the force from the engine cannot be greater than all the forces of friction, otherwise the net force cannot be zero.

b) the net force on the car is zero.  --> TRUE, for what we said at point A)

c) the inertia is changing.  --> FALSE. The inertia of an object just depend on the mass and the velocity of the object: as neither the mass nor the velocity are changing in this problem, then the inertia of the car is not changing.

d) the forces of friction are proportional to the acceleration of the car.  --> FALSE. Generally, the force of friction acting on an object moving on a flat surface is

F_f = \mu mg

where \mu is the coefficient of friction, m is the mass, and g the acceleration of gravity. Therefore, the force of friction does not depend on the acceleration of the car.

e) All of the above. --> FALSE

Learn more about net force and Newton's second law:

brainly.com/question/3820012

#LearnwithBrainly

6 0
3 years ago
Describe the results of Ernest Rutherford's gold-foil experiment and explain how his results changed ideas about the distributio
DochEvi [55]
In Rutherford's gold foil experiment, some of the positive particles would pass through the foil and some would bounce off. This led to a new theory that all of the positive subatomic particles were in the center of the atom instead of evenly spread throughout.
4 0
3 years ago
A 1300 kg car traveling with a speed of 3.5 m/s executes a turn with a 8.5 m radius of curvature.
Y_Kistochka [10]

Answer:

1.4 m/s/s (2.s.f)

Explanation:

The formula for centripetal acceleration is:

a=\frac{v^{2} }{r}, where v is velocity and r is the radius.

In the question we are given the information that the car has a mass of 1300kg, a velocity of 2.5m/s, and a turn radius of 8.5m which are all the values we need. Therefore we can simply substitute in the values to solve the question:

a=\frac{3.5^{2} }{8.5} \\a=1.4

Therefore the centripetal acceleration of the car is 1.4m/s/s. (2.s.f)

Hope this helped!

7 0
3 years ago
How did planck find the correct curve for the specturm of light emitted by a hot obkect?
Neko [114]

Planck find the correct curve for the specturm of light emitted by a hot object by vibrational energies of the atomic resonators were quantized.

<h3>Briefing :</h3>
  • The energy density of a black body between λ and λ + dλ is the energy E=hc/λ of a mode times the density of states for photons, times the probability that the mode is occupied. 
  • This is Planck's renowned equation for a black body's energy density.
  • According to this, electromagnetic radiation from heated bodies emits in discrete energy units or quanta, the size of which depends on a fundamental physical constant (Planck's constant). The basis of infrared imaging is the correlation between spectral emissivity, temperature, and radiant energy, which is made possible by Planck's equation.

Learn more about the Planck's constant with the help of the given link:

brainly.com/question/27389304

#SPJ4

3 0
1 year ago
Other questions:
  • If the threshold wavelength for copper is 2665 A, calculate the maximum kinetic energy of a photoelectron generated by ultraviol
    5·1 answer
  • Will give brainliest!
    8·1 answer
  • A child walks 5.0 meters north, then 4.0 meters east, and finally 2.0 meters south. what is the magnitude of the resultant displ
    14·2 answers
  • What is wave speed measured in?
    10·1 answer
  • In this section we considered a circular parallel-plate capacitor with a changing electric field. Describe the induced magnetic
    8·1 answer
  • What test is an aptitude test
    15·2 answers
  • What must the charge (sign and magnitude) of a particle of mass 1.40 gg be for it to remain stationary when placed in a downward
    11·1 answer
  • Please Help! If you dont know the answers please dont answer! i will give you brrainlist! if you complete correctly!
    14·1 answer
  • Jenny puts a book on her desk. Jenny’s book has an area of 200 cm2.It exerts a pressure of 0.05 N/cm2 on the desk. What is the w
    7·1 answer
  • how is the rate of evporation of a liquid affected by temperature, the surface area of a liquid exposed to air
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!