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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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Two people were pulling this thing with 560 Newton. Now they are using a rope with 50°. How much Newton would they need to pull
Brums [2.3K]

Answer:

10 N

Explanation:

While many people would like to simply add the forces from each end to get a total force, this is fundamentally incorrect.

MIGHT BE TOTALLY WRONG

4 0
2 years ago
12. An organ pipe that is 1.75 m long and open at both ends produces sound of
podryga [215]

Answer:

354 m/s

Explanation:

For the second overtune (Third harmonic) of an open pipe,

λ = 2L/3................................ Equation 1

Where L = Length of the open pipe, λ = Wave length.

Given: L = 1.75 m.

Substitute into equation 1

λ = 2(1.75)/3

λ = 1.17 m.

From the question,

V = λf.......................... Equation 2

V = speed of sound in the room, f = frequency

Given: f = 303 Hz.

Substitute into equation 2

V = 1.17(303)

V = 353.5

V ≈ 354 m/s

Hence the right answer is 354 m/s

8 0
3 years ago
A(n) ________ is a specialized bursa that wraps around a tendon to reduce friction.
Kisachek [45]

Tendon Sheath - is a specialized bursa that wraps around a tendon to reduce friction.

<h3>What is Tendon Sheath ?</h3>

Tendon Sheath is a thin layer of tissue, surrounds each tendon in our body. The tendon sheath can also be called synovial lining or fibrous sheath. Tendon sheaths help to protect tendons from abrasive damage as they move.

Connection between Bursa and Tendon Sheath : Bursae are small fluid-filled sacs that can lie under a tendon, cushioning the tendon and protecting it from the injury. Bursae also provides an extra cushioning to adjacent structures that otherwise might rub against each other, which will cause wear and tear ( example, between a bone and a ligament ) .

So, lastly we can say that Tendon Sheath is the specialized bursa that wraps around a tendon to reduce friction.

To know more about Tendon Sheath please click here : brainly.com/question/17087116

#SPJ4

8 0
11 months ago
What does the negative sign in F = –kx mean?
Andru [333]
The force is opposite to the displacement
3 0
3 years ago
A car is traveling in uniform circular motion on a section of flat roadway whose radius is . The road is slippery, and the car i
Alona [7]

Answer:

The smallest radius will be four (4) times the initial radius

Explanation:

The car maintains a constant angular speed. According to Newton's Second Law F = m a

1. F_{r}=m*A_{n}

2. A_{n}=\frac{v^2}{R_{p}}

Replacing 2 in 1

3. F_{r}=m*\frac{v^2}{R_{p}}

Where:

Fr= Frictional force

Rp= Initial Radius

An= Centripetal Acceleration

M= Mass

V= Velocity

Also we have that:

4. F_{r}=\mu *W=\mu*m*g

μ= Coefficient of friction between the car and the surface

M= Mass

W= Weight

G= Gravity

r is cleared from equation 3

5. R_{p}=m*\frac{v^2}{F_{r}}

Replacing 4 in 5

6. R_{p}=m*\frac{v^2}{\mu*m*g}

Simplifying

7. R_{p}=\frac{v^2}{\mu*g}

Now we have a new velocity equal to twice the initial velocity, We replace it by 2v in equation 7

8. R_{n}=\frac{(2v)^2}{\mu*g}

Computing

9. R_{n}=\frac{4v^2}{\mu*g}

Replacing 5 in 9

R_{n}=4*R_{p}

8 0
3 years ago
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