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Maslowich
3 years ago
14

When the distance between a point source of light and a light meter is reduced from 6.0m to 2.0 m, the intensity of illumination

at the meter will be the original value multiplied by _____.
Physics
1 answer:
Sergeeva-Olga [200]3 years ago
7 0

Answer:

Explanation:

Let the point source have power P .

At distance r , the intensity I

I = P / 4πr² . If intensity at 6 m and 2 m be I₁ and I₂

I₁ = P / 4π x 6²

I₂ =  P / 4π x 2²

I₁ / I₂ = 2² / 6²

= 1 / 9

I₂ = 9 I₁

Intensity will be 9 times that at 6 m .

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Which of the following air conditions would be least likely to have precipitation? A. warm, dry air B. warm, moist air C. cold,
hram777 [196]

Answer:

C

Explanation:

when it's cold,the water vapour that atmosphere can hold is much lower....and when moist air have so much water vapour in it...perfect condition for precipitation

8 0
3 years ago
A ball on a string travels once around a circle with a circumference of 2. 0 m. The tension in the string is 5. 0 n.
Schach [20]

The work done by the ball on a string is 0J if a ball is travelling around as circle with a circumference of 2.0m

We know that circumference or perimeter of circle=2πr where r is the radius of the circle.

So, we have circumference=2m

Therefore,2πr=2

=>r=2/2π

=>r=(1/π) m

Now, we know very well that when a body moves a displacement dx under the action of force, some amount of work is done by the force on the body and that force is given by

W=\int\limits {F}. \, dx

where F is defined as the force acting on the body

and dx is the displacement of the body.

On expanding the above formula, we get

=>W=Fdxcosθ where cosθ is the angle between the force and displacement of the body.

Since Tension is actually centripetal force which is acting along the center of the circle where ball displacement is in perpendicular direction to the tension.

It means angle between Tension and ball's displacement is 90°. So,cos90°=0

Therefore, W=Fdxcos90

=>W=0J.

Hence, amount of work done is 0J.

To know more about work, visit here:

brainly.com/question/18094932

#SPJ4

(Complete question) is:

A ball on a string travels once around a circle with a circumference of 2. 0 m. The tension in the string is 5. 0 N. What amount of work done by the ball on the string?

4 0
1 year ago
What does the phrase “constant velocity” indicate?
pickupchik [31]
The answer is C is the velocity is the same then the acceleration is also the same.
3 0
3 years ago
when sound would travel faster...through a piece of wood that floats in water or a piece of steel that sinks in water
Musya8 [376]
Through piece of Steel
5 0
3 years ago
Read 2 more answers
A forklift raises a crate weighing 8.35 × 102 newtons to a height of 6.0 meters. What amount of work does the forklift do?
Vinil7 [7]
Answer:

<span>5010J</span>

Explanation:

Work is force times distance, or

<span>W=F⋅d</span>.

Substitute in values from the question to get

<span>W=8.35⋅<span>102</span>N⋅6m=50.1⋅<span>102</span>Nm=5010<span>J</span></span>

6 0
3 years ago
Read 2 more answers
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