All categories

3 years ago

The value of efficiency is never 100% or more in practice. why

1 answer:

3 0

Answer: Because of presence of friction in most cases as friction exists in ever machine/body, so whenever it works, friction causes heat and sound energy as well, hence, proving that a system cannot be 100% efficient due to friction.

You might be interested in

Two infinite plane sheets with uniform surface charge densities are placed parallel to each other with separation d. in the regi

kupik [55]

Answer:Uniform between the plates

Explanation:

Electric Field due to infinite sheet with uniform charge is given by

$E=\dfrac{\sigma }{\epsilon _0}$

Where $\sigma$ =charge density

$\epsilon _0$ =Space Permittivity

From the formula we can see that Electric field is independent of distance of the particle, so it is uniform between the plates .

3 0

2 years ago

What is another name for the heat-trapping gases

marissa [1.9K]

Greenhouse Gases, on relation to Earth's atmosphere.

7 0

3 years ago

Which of the following are events?

ira [324]

Answer:

G..................

3 0

2 years ago

Assume the motions and currents mentioned are along the x axis and fields are in the y direction. (a) does an electric field exe

matrenka [14]

(a) does an electric field exert a force on a stationary charged object?
Yes. The force exerted by an electric field of intensity E on an object with charge q is
 $F=qE$
As we can see, it doesn't depend on the speed of the object, so this force acts also when the object is stationary.

(b) does a magnetic field do so?
No. In fact, the magnetic force exerted by a magnetic field of intensity B on an object with charge q and speed v is
 $F=qvB \sin \theta$
where $\theta$ is the angle between the direction of v and B.
As we can see, the value of the force F depends on the value of the speed v: if the object is stationary, then v=0, and so the force is zero as well.

(c) does an electric field exert a force on a moving charged object?
Yes, The intensity of the electric force is still
 $F=qE$
as stated in point (a), and since it does not depend on the speed of the charge, the electric force is still present.

(d) does a magnetic field do so?
Yes. As we said in point b, the magnetic force is
$F=qvB \sin \theta$
And now the object is moving with a certain speed v, so the magnetic force F this time is different from zero.

(e) does an electric field exert a force on a straight current-carrying wire?
Yes. A current in a wire consists of many charges traveling through the wire, and since the electric field always exerts a force on a charge, then the electric field exerts a force on the charges traveling through the wire.

(f) does a magnetic field do so?
Yes. The current in the wire consists of charges that are moving with a certain speed v, and we said that a magnetic field always exerts a force on a moving charge, so the magnetic field is exerting a magnetic force on the charges that are traveling through the wire.

(g) does an electric field exert a force on a beam of moving electrons?
Yes. Electrons have an electric charge, and we said that the force exerted by an electric field is
 $F=qE$
So, an electric field always exerts a force on an electric charge, therefore on an electron beam as well.

(h) does a magnetic field do so?
Yes, because the electrons in the beam are moving with a certain speed v, so the magnetic force
 $F=qvB \sin \theta$
is different from zero because v is different from zero.

6 0

3 years ago

An athlete whirls a 7.00 kg hammer 1.8 m from the axis of rotation in a horizontal circle, as

iogann1982 [59]

Answer:

A-500 N

Explanation:

The computation of the tension in the chain is shown below

As we know that

F = ma

where

F denotes force

m denotes mass = 7

And, a denotes acceleration

Now for the acceleration we have to do the following calculations

The speed (v) of the hammer is

v = Angular speed × radius

where,

Angular seed = 2 × π ÷ Time Period

So, v = 2 × π × r ÷ P

v = 2 × 3.14 × 1.8 ÷ 1

= 11.304 m/s

Now

a = v^2 ÷ r

= 70.98912 m/s^2

Now the tension is

T = F = m × a

= 7 × 70.98912

= 496.92384 N

= 500 N

5 0

2 years ago

The value of efficiency is never 100% or more in practice. why​

The value of efficiency is never 100% or more in practice. why