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4 years ago

What causes long sightedness?how is it corrected.

Physics

1 answer:

NNADVOKAT [17]4 years ago

4 0

Answer:

Long sight occurs when the eyeball is too short or the lens is too thin, or both. As a result, light rays from near objects are focused behind the retina because the light rays are not converged enough. The image formed on the retina is therefore out of focus.

To correct this problem, people can wear glasses with convex lenses. Light rays from near objects are converged by the convex lenses before entering the eyes, so that light can be focused on the retina to form a sharp image. Additionally, long sight can also be corrected by surgical methods such as LASIK.

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A plane mirror forms a virtual image. give reasons

xenn [34]

Answer:

1. The reason why a plane mirror forms a virtual image is because it doesn't let the light go through it, but it reflects the light, so if you go behind the plane mirror, then you won't see the rays of light since it's not letting the rays of light go behind it.

2. The image cannot be projected onto a screen also.

3. Also, the Rays of light never meet at a focus point, so hence, this is why the plane mirror forms a virtual image.

Thanks!

4 0

2 years ago

Read 2 more answers

A 2kg blob of putty moving at 4 m/s slams into a 6kg blob of putty at rest what is the speed of the to stick together blobs imme

andrew11 [14]

<h2>Answer</h2>

1m/s

<h2>Explanation</h2>

Given that:

<em>Mass of first blob = 2kg = m1</em>

<em>Velocity of blob = 4m/s = v1</em>

<em>Mass of second blob = 6kg = m2</em>

<em>Velocity of blob = 0m/s = v2</em>

<em />

To find:

<em>Final velocity = Vf</em>

<em />

<em>This question is of inelastic collision which is any collision between objects in which some energy is lost.</em>

<em />

<h3>Formula to be use:</h3><h2>(m1*v1) + (m2*V2) = Vf(m1 + m2)</h2>

(2*4) + (6*0) = Vf(2+6)

8 + 0 = Vf(8)

8 = Vf(8)

Vf = 1 m/s

So the speed of two blobs immediately after colliding = 1 m/s

3 0

3 years ago

Calculate the momentum, A bald eagle with a mass of 26.4 kg and velocity of 15.6 m/s

AveGali [126]

Answer:

Explanation:

Formula :

<u>Momentum = mass × velocity</u>

<u />

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

Given :

⇒ mass = 26.4 kg

⇒ velocity = 15.6 m/s

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

Solving :

⇒ Momentum = 26.4 × 15.6

⇒ Momentum = <u>411.84 kg m/s</u>

3 0

2 years ago

A drag racer starts from rest and accelerates at 7.4 m/s2. How far will he travel in 2.0 seconds?

3241004551 [841]

Using the kinematic equation below we can determine the distance traveled if t=2, a=7.4m/s^2. First we must determine the final velocity:

$v_{final}=v_{initial}+\frac{1}{2}at\\\\v_{final}=0+(7.4m/s^2)(2s)=34.8m/s$

Now we will determine the distance traveled:

$v_{final}^2=v_{initial}^2+2a \Delta x\\\\\Delta x = \frac{v_{final}^2}{2a} =\frac{(34.8)^2}{(2)(7.4)}=81.83 m$

Therefore, the drag racer traveled 81.83 meters in 2 seconds.

4 0

3 years ago

The drawing shows three different resistors in two different circuits. the battery has a voltage of v = 23 v, and the resistors

vesna_86 [32]

Missing picture in the text. I've found it here:
https://www.flickr.com/photos/[email protected]/6791933847/in/photostream

Solution:

Circuit 1)
The three resistors are in series. So the equivalent resistance of the circuit is
$R_{eq}=R_1+R_2+R_3 =50.0\Omega+25.0 \Omega+10.0 \Omega=85.0 \Omega$
So the current flowing through each resistor is the same, and it is given by Ohm's law:
$I= \frac{V}{R_{eq}}= \frac{23 V}{85.0 \Omega}=0.27 A$

And the voltage drop across each resistor is given by Ohm's law as well:
$V_1 = I R_1 = (0.27 A)(50.0 \Omega)=13.5 V$
$V_2 = I R_2 = (0.27 A)(25.0 \Omega)=6.8 V$
$V_3 = I R_3 = (0.27 A)(10.0 \Omega)=2.7 V$

Circuit 2)
The three resistors are in parallel, so their equivalent resistance is given by
$\frac{1}{R_{eq}}= \frac{1}{R_1}+ \frac{1}{R_2}+ \frac{1}{R_3}= \frac{1}{50\Omega}+ \frac{1}{25 \Omega}+ \frac{1}{10 \Omega}= \frac{7}{50 \Omega}$
$R_{eq}= \frac{50}{7} \Omega=7.1 \Omega$

The voltage drop across each resistor is the same, and it is equal to the voltage of the battery:
$V_1 = V_2 = V_3 = 23 V$

while the current across each resistor is given by Ohm's law:
$I_1 = \frac{V}{R_1}= \frac{23 V}{50 \Omega}=0.46 A$
$I_2 = \frac{V}{R_2}= \frac{23 V}{25.0 \Omega}=0.92 A$
$I_3 = \frac{V}{R_3}= \frac{23 V}{10 \Omega}=2.3 A$

5 0

3 years ago