HELP URGENT!!!!!!!!!!!!!!!!!!!!!!!!

By what factor must the amplitude of a sound wave be increased in order to increase the intensity by a factor of 9?a. 9 b. 2 c.

Marta_Voda [28]

Answer:

option D

Explanation:

given,

$intensity\ \alpha \ (Amplitude)^2$

increase the intensity by factor of 9

I₁ = I₀

I₂ = 9 I₀

now,

$\dfrac{I_1}{I_2}=\dfrac{A_1^2}{A_2^2}$

$\dfrac{I_0}{9I_0}=(\dfrac{A_1}{A_2})^2$

$(\dfrac{A_1}{A_2})^2=\dfrac{1}{9}$

$\dfrac{A_1}{A_2}=\dfrac{1}{3}$

A₂ = 3 A₁

hence, amplitude increase with the factor of 3

so, the correct answer is option D

4 0

3 years ago

Read 2 more answers

When reaching a boundary between two media (1 and 2), an incident ray is partially reflected and partially refracted. The ray is

lukranit [14]

Answer:

The angle of incidence when the reflected ray is perpendicular to the incident ray = 45°

Explanation:

According to Snell's Law,

n₁ sin θ₁ = n₂ sin θ₂

When the angle between the incident ray and reflected ray is 90°, the angle of incidence is θ₁ and the angle of reflection, θ₂ = 90° - θ₁ and the index of refraction in the Snell's Law for both media would be the same, n₁ = n₂ = n

n sin θ₁ = n sin (90° - θ₁)

Note that from trigonometric relations,

Sin (90° - θ₁) = cos θ₁

n sin θ₁ = n cos θ₁

(sin θ₁)/(cos θ₁) = 1

tan θ₁ = 1

θ₁ = arctan 1 = 45°

Hope this Helps!!!

7 0

3 years ago

Read 2 more answers

A spaceship hovering over the surface of Venus drops an object from a height of 17 m. How much longer does it take to reach the

Paraphin [41]

1.96s and 1.86s. The time it takes to a spaceship hovering the surface of Venus to drop an object from a height of 17m is 1.96s, and the time it takes to the same spaceship hovering the surface of the Earth to drop and object from the same height is 1.86s.

In order to solve this problem, we are going to use the motion equation to calculate the time of flight of an object on Venus surface and the Earth. There is an equation of motion that relates the height as follow:

$h=v_{0} t+\frac{gt^{2}}{2}$

The initial velocity of the object before the dropping is 0, so we can reduce the equation to:

$h=\frac{gt^{2}}{2}$

We know the height h of the spaceship hovering, and the gravity of Venus is $g=8.87\frac{m}{s^{2}}$ . Substituting this values in the equation $h=\frac{gt^{2}}{2}$ :

$17m=\frac{8.87\frac{m}{s^{2} } t^{2}}{2}$

To calculate the time it takes to an object to reach the surface of Venus dropped by a spaceship hovering from a height of 17m, we have to clear t from the equation above, resulting:

$t=\sqrt{\frac{2(17m)}{8.87\frac{m}{s^{2} } }} =\sqrt{\frac{34m}{8.87\frac{m}{s^{2} } } }=1.96s$

Similarly, to calculate the time it takes to an object to reach the surface of the Earth dropped by a spaceship hovering from a height of 17m, and the gravity of the Earth $g=9.81\frac{m}{s^{2}}$ .

$t=\sqrt{\frac{2(17m)}{9.81\frac{m}{s^{2} } }} =\sqrt{\frac{34m}{9.81\frac{m}{s^{2} } } }=1.86s$

8 0

3 years ago

Read 2 more answers

Menciona generaciones de particulas y explique cada una

Readme [11.4K]

ENGLISH:

It distinguishes between the fermions, which are particles of matter, and the bosons, which carry forces. The matter particles include six quarks and six leptons. The six quarks are called the up, down, charm, strange, top and bottom quark. ... All of these matter particles fall into three “generations.”

SPANISH:

Distingue entre los fermiones, que son partículas de materia, y los bosones, que transportan fuerzas. Las partículas de materia incluyen seis quarks y seis leptones. Los seis quarks se denominan quark arriba, abajo, encanto, extraño, superior e inferior. ... Todas estas partículas de materia se dividen en tres "generaciones".

3 0

3 years ago

It is safer for a car driver to be wearing a seat belt, compared with not wearing a seat belt, if the car is involved in a colli

Korolek [52]

Explanation: It is because when a car is moving both the car and the driver is in inertia of motion. When a car is involved in collision it comes to a sudden stop and the car comes into inertia of rest whereas the person still in inertia of motion moves forward and might result in major injuries. But this can be prevented by wearing a seatbelt

Hope it helps :)

8 0

3 years ago