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Stolb23 [73]
3 years ago
11

At what distance will a 80 W lightbulb have the same apparent brightness as a 120 W bulb viewed from a distance of 40 m

Physics
1 answer:
liq [111]3 years ago
4 0

Answer:

32.6mm

Explanation:

Using area of a sphere(bulb) = 4πr²

So A is proportional to radius²

So the Energy will be proportional to r²

But 120/80 = 1.5 is the energy factor so

Using

1.5/d² = 1/r²

1.5/40²= 1/r^2

r = √( 40²/ 1.5)

r = 32.6m

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Precision is how close a series of measurements are to ______
Leya [2.2K]

Answer:

Accuracy is how close a measured value is to an accepted value. <u>Precision is how close measurements are to one another.</u> To make measurements, you have to evaluate both the accuracy and the precision to get a correct value.

3 0
2 years ago
Consider the 65 N light fixture supported as in the figure. Find the tension in the supporting wires.
ASHA 777 [7]

By using Lami's theorem formula, the tension in the supporting wires is 48.6 Newtons

TENSION

  • Tension is also a force having Newton as S.I unit.
  • The tension in the wire will be the same.

This question can be solved by using either vector diagram or by using  Lami's theorem.

The sum of two given angles  = 42 + 42 = 84 degrees

The third angle = 180 - 84 = 96 degrees.

Below is the Lami's theorem formula

\frac{T}{sin\alpha } = \frac{T}{sin\beta } = \frac{W}{sinY}

Where

\alpha  = \beta = 42 + 90 = 132 degrees

Y = 96 degrees

W = 65 N

By using the formula, we have

\frac{T}{sin\alpha } =  \frac{W}{sinY}

T/sin 132 = 65/sin96

Cross multiply

T = 0.743 x 65.57

T = 48.56 N

Therefore, the tension in the supporting wires is 48.6 Newtons approximately.

Learn more about Tension here: brainly.com/question/24994188

3 0
2 years ago
Raising 100 grams of water from 40 to 60 °C (the specific heat capacity of water is 1
ANTONII [103]
C. 2000 calories.

Explanation/calculation:

Specific heat capacity = calories / mass * (final temperature - initial temperature)

1 = calories / 100 * (60 - 40)
1 = calories / 100 * 20
1 * (100 * 20) = calories
1 * 2000 = calories
2000 = calories
5 0
3 years ago
Read 2 more answers
What is the relation between force and acceleration ?​
stepladder [879]

Explanation:

Newton's second law shows that there is a direct relation ship between force and acceleration . the grater force that is applied on a object of given mass the more the accelerate. for example doubling the force in the object doubles it's acceleration.

8 0
3 years ago
Read 2 more answers
A particle with a charge of 4.4 * 10^-5 C is released in an electric field whose magnitude is 750 N/C. What is the force that th
padilas [110]

Answer:

F = 3.3×10^ -2 N

.................

4 0
3 years ago
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