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4 years ago

What do lenses do?

2 answers:

3 0

A convex lens makes light rays converge (come together) at the focal point or focus. The distance from the center of the lens to the focal point is the focal length of the lens. Convex lenses are used in things like telescopes and binoculars to bring distant light rays to a focus in your eyes.

strojnjashka [21]4 years ago

3 0

B:refract light when a focused beam of light hits the lens it splits apart into smaller beams

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This is the last question

koban [17]

Answer:

It's C

Explanation:

3 0

3 years ago

The depth of the Pacific Ocean in the Mariana Trench is 36,198 ft. What is the gauge pressure at this depth

FinnZ [79.3K]

Answer:

the pressure at the depth is 1.08 × $10^{8}$ Pa

Explanation:

The pressure at the depth is given by,

P = h $\rho$ g

Where, P = pressure at the depth

h = depth of the Pacific Ocean in the Mariana Trench = 36,198 ft = 11033.15 meter

$\rho$ = density of water = 1000 $\frac{kg}{m^{3} }$

g = acceleration due to gravity ≈ 9.8 $\frac{m}{s^{2} }$

P = 11033.15 × 9.8 × 1000

P = 1.08 × $10^{8}$ Pa

Thus, the pressure at the depth is 1.08 × $10^{8}$ Pa

4 0

3 years ago

A 26 foot ladder is lowered down a vertical wall at a rate of 3 feet per minute. The base of the ladder is sliding away from the

lakkis [162]

Answer:

(i) 7.2 feet per minute.

(ii) No, the rate would be different.

(iii) The rate would be always positive.

(iv) the resultant change would be constant.

(v) 0 feet per min

Explanation:

Let the length of ladder is l, x be the height of the top of the ladder from the ground and y be the length of the bottom of the ladder from the wall,

By making the diagram of this situation,

Applying Pythagoras theorem,

$l^2 = x^2 + y^2-----(1)$

Differentiating with respect to t ( time ),

$0=2x\frac{dx}{dt} + 2y\frac{dy}{dt}$ ( l = 26 feet = constant )

$\implies 2y\frac{dy}{dt} = -2x\frac{dx}{dt}$

$\implies \frac{dy}{dt}=-\frac{x}{y}\frac{dx}{dt}$

We have,

$y = 10, \frac{dx}{dt}= -3\text{ feet per min}$

$\frac{dy}{dt}=\frac{3x}{10}-----(X)$

(i) From equation (1),

$26^2 = x^2 + 10^2$

$676=x^2 + 100$

$576 = x^2$

$\implies x = 24\text{ feet}$

From equation (X),

$\frac{dy}{dt}=\frac{3\times 24}{10}=7.2\text{ feet per min}$

(ii) From equation (X),

$\frac{dy}{dt}\propto x$

Thus, for different value of x the value of $\frac{dy}{dt}$ would be different.

(iii) Since, distance = Positive number,

So, the value of y will always a positive number.

Thus, from equation (X),

The rate would always be a positive.

(iv) The length of the ladder is constant, so, the resultant change would be constant.

i.e. x = increases ⇒ y = decreases

y = decreases ⇒ y = increases

(v) if ladder hit the ground x = 0,

So, from equation (X),

$\frac{dy}{dt}=0\text{ feet per min}$

3 0

3 years ago

A cheetah runs 5 miles in 60 seconds. How fast did the cheetah run in MILES per HOUR? Convert seconds into hours first, then sol

Vinil7 [7]

Answer:

300 miles per hour

Explanation:

Speed is distance per unit time, expressed as s=d/t where t is the time taken, d is distance covered and s is the speed.

Convering s to hrs

To convert seconds to hours, we knkw that 1 hour has 60 minutes and each minute has 60 seconds. Therefore, 1 hour has 60*60=3600 seconds

If 3600s=1 h

60 s=?

By cross multiplication 60s*1 h/3600s=1/60 hours

Given distance as 5 miles and time as 1/60 hours then the speed will be 5 divided by 1/60 hrs which is equivalent to 5*60=300 miles per hour

6 0

3 years ago

an object 50 cm high is placed 1 m in front of a converging lens whose focal length is 1.5 m. determine the image height (in cm)

Juli2301 [7.4K]

Given :

An object 50 cm high is placed 1 m in front of a converging lens whose focal length is 1.5 m.

To Find :

the image height (in cm).

Solution :

By lens formula :

$\dfrac{1}{v} - \dfrac{1}{u} = \dfrac{1}{f}$

Here, u = - 100 cm

f = 150 cm

$\dfrac{1}{v} - \dfrac{1}{-100} = \dfrac{1}{150}\\\\v = - 300 \ cm$

Now, magnification is given by :

$m = \dfrac{v}{u} = \dfrac{h_i}{h_o}\\\\h_i = \dfrac{300}{100}\times 1\\\\h_i = 3 \ m$

Therefore, the image height is 3 m or 300 cm.

5 0

3 years ago