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2 years ago

the person is not able to see the far lying object clearly. which type of lens will the doctor prescribe him give reason?

Physics

1 answer:

ASHA 777 [7]2 years ago

8 0

Answer:

correction of farsightedness uses a converging lenses that compensates for the under convergence by the eye. the converging lens produces an image farther from the eye than the object so that farsighted can see it clearly.

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Children's immune systems are very active and excludes them from being a high risk to foodbourne illness.

Alex17521 [72]

Answer:

TRUE...is ans........

8 0

3 years ago

A plastic film moves over two drums. During a 4-s interval the speed of the tape is increased uniformly from v0 = 2ft/s to v1 =

Ratling [72]

Answer:

Question 1)

a) The speed of the drums is increased from 2 ft/s to 4 ft/s in 4 s. From the below kinematic equations the acceleration of the drums can be determined.

$v_1 = v_0 + at \\4 = 2 + 4a\\a = 0.5~ft/s^2$

This is the linear acceleration of the drums. Since the tape does not slip on the drums, by the rule of rolling without slipping,

$v = \omega R\\a = \alpha R$

where α is the angular acceleration.

In order to continue this question, the radius of the drums should be given.

Let us denote the radius of the drums as R, the angular acceleration of drum B is

α = 0.5/R.

b) The distance travelled by the drums can be found by the following kinematics formula:

$v_1^2 = v_0^2 + 2ax\\4^2 = 2^2 + 2(0.5)x\\x = 12 ft$

One revolution is equal to the circumference of the drum. So, total number of revolutions is

$x / (2\pi R) = 6/(\pi R)$

Question 2)

a) In a rocket propulsion question, the acceleration of the rocket can be found by the following formula:

$a = \frac{dv}{dt} = -\frac{v_{fuel}}{m}\frac{dm}{dt} = -\frac{13000}{2600}25 = 125~ft/s^2$

b) $a = -\frac{v_{fuel}}{m}\frac{dm}{dt} = - \frac{13000}{400}25 = 812.5~ft/s^2$

5 0

3 years ago

Help a girl out ?! Plz ill give brainlest

shepuryov [24]

Answer:

I am pretty sure it is B.

Explanation:

I hope this helped if it didn't I am truly sorry

5 0

2 years ago

Read 2 more answers

What is the source of all electromagnetic waves?

kherson [118]

Answer:

Accelerating charges.

Explanation:

Electromagnetic waves are waves produced by the vibration of both electrical and magnetic fields.

This interaction produces an energy source that does not require any medium to propagate.

To produce electromagnetic waves, electric and magnetic fields must be vibrating.

An electric charge produced when vibrating under voltage will produce electromagnetic waves. This is the same for all sources of these waves.

The sun produces electromagnetic waves. A lot of human activities also does this.

6 0

3 years ago

What eccentricity value results in a circular orbit?

Oxana [17]

Answer:

Zero

Explanation:

Given the equation of an ellipse:

$\frac{x^2}{a^2}+\frac{y^2}{b^2}=1$

The eccentrity of an ellipse is given by:

$e=\sqrt{1-\frac{b^2}{a^2}}$

For a circle, we have

$a=b$

Therefore the eccentricity of a circle is

$e=\sqrt{1-\frac{1^2}{1^2}}=0$

7 0

2 years ago