Light described as what two things?

Why does a balloon fully inflated with air rise up vertically for some distance whenpunctured from below?

Virty [35]

Newton's second and third law can be found the correct answer is:

The force of the air leaving the balloon by action and reaction causes it to have a positive acceleration upward and rise.

Pressure is defined by the relationship between forces and area,

P = F / A

Where P is pressure, F is force and A is area

F = P A

Newton's second law is that the sum of the external forces of a body is proportional to the mass of the body and the acceleration

Newton's third law or action and reaction says that forces in nature appear in pairs on the two interacting bodies, the magnitude of the force is equal, but in the opposite direction; each one is applied to one of the bodies.

A free-body diagram of the process is shown in the attachment

B + F - W = m a

W = m g

Where B is the thrust, F the force of air exit, W the weight, m the mass and the acceleration of the body

Archimedes' principle states that the vertical thrust on a body is equal to the fart of the dislodged fluid, in this case air.

B =ρ_{air} g V_{air}

Where ρ and V_ {air} are the density and volume of the air, respectively,

It's substitute

ρ_{air} g V_{air} + P A - m g = m a

a =

The mass of the body is formed by the mass of the balloon plus the mass of air that it contains

Let's analyze this expression in three moments

Before opening the hole at the bottom. The second term is zero, so the thrust is not enough to lift the balloon, the acceleration is negative.

Just after opening. The force of the air coming out that by the law of action and reaction creates a force of equal magnitude and upward direction on the balloon. The sum of these two forces makes the acceleration positive, therefore the balloon rises

After the pressure inside the balloon is equal to the atmospheric pressure. Tthis case the second term is zero again and the balloon begins to descend with an acceleration less than the acceleration of gravity.

In conclusion with Newton's second and third law we find the correct answer is:

The force of the air leaving the balloon by action and reaction law causes it to have a positive acceleration upward and rise.

Learn more about Newton's law here:

brainly.com/question/13959891

6 0

3 years ago

Soap bubbles can display impressive colors, which are the result of the enhanced reflection of light of particular wavelengths f

Bogdan [553]

Answer:

the minimum wall thickness that will enhance the reflection of light is 146.9 nm

Explanation:

Given the data in the question;

At the first interface, a phase shift occurs as the incident light is in air that has less refractive index compare to the thin film of soap bubble.

At the second interface, no shift occurs,

condition for constructive interference;

t = ( m + 1/2) × λ/2n

where m = 0, 1, 2, 3 . . . . . .

now, the condition for the constructive interference;

t = mλ/2n

where t is the thickness of the soap bubble, λ is the wavelength of light and n is the refractive index of soap bubble.

so the minimum thickness of the film which will enhance reflection of light will be;

t $_{min$ = ( m + 1/2) × λ/2n

we substitute

t $_{min$ = ( 0 + 1/2) × 711 /2(1.21)

t $_{min$ = 0.5 × 711/2.42

t $_{min$ = 0.5 × 293.80165

t $_{min$ = 146.9 nm

Therefore, the minimum wall thickness that will enhance the reflection of light is 146.9 nm

8 0

3 years ago

I NEED HELP ASAP!!!!!

Ratling [72]

Answer:

D) momentum of cannon + momentum of projectile= 0

Explanation:

The law of conservation of momentum states that the total momentum of an isolated system is constant.

In this case, the system cannon+projectile can be considered as isolated, because no external forces act on it (in fact, the surface is frictionless, so there is no friction acting on the cannon). Therefore, the total momentum of the two objects (cannon+projectile) must be equal before and after the firing:

$p_i = p_f$

But the initial momentum is zero, because at the beginning both the cannon and the projectile are at rest:

$p_i = 0$

So the final momentum, which is sum of the momentum of the cannon and of the projectile, must also be zero:

$p_f = p_{cannon}+p_{projectile} =0$

6 0

4 years ago

A girl walks 5km due north,then in the direction of 60° of northeast towards her final destination.If the magnitude of her resul

storchak [24]

Answer:

4.2 km

Explanation:

A triangle is a polygon with three sides and three angles. There are different types of triangles such as isosceles triangle, scalene triangle, equilateral triangle and right angled triangle.

Sine rule states that for a triangle with angles A,B and C and corresponding opposite sides a, b, and c, the following formula holds:

$\frac{a}{sin(A)}=\frac{b}{sin(B)}=\frac{c}{sin(C)}$

Let the starting point be A, hence the side opposite to the angle = a = distance travelled in north east direction.

Let the point of 60° of northeast be B = 90° + (90° - 60°) = 120°, hence the side opposite to the angle = b = resultant displacement = 8 km.

Let C be the endpoint, hence the side opposite to the angle = c = distance travelled north = 5 km

Using sine rule:

$\frac{b}{sin(B)}=\frac{c}{sin(C)} \\\\\frac{8}{sin(120)}=\frac{5}{sin(C)} \\\\sin(C)=\frac{5*sin(120)}{8} =0.5412\\\\C=sin^{-1}(0.5412)=32.8^o\\\\$

∠A + ∠B + ∠C = 180° (sum of angle in a triangle)

∠A + 120 + 32.8 = 180

∠A = 27.2°

$\frac{b}{sin(B)}=\frac{a}{sin(A)} \\\\\frac{8}{sin(120)}=\frac{a}{sin(27.2)} \\\\a=\frac{8*sin(27.2)}{sin(120)} \\\\a=4.2\ km$

Therefore she travelled 4.2 km in the north east direction

5 0

3 years ago

What are the benefits and harms of protists? WILL GIVE BRAINLIEST FOR THE PERFECT ANSWER

alina1380 [7]

Answer:

<em>Well, Many protists are harmful to humans, other animals and plants because they cause diseases and crop failures. However, some protists are actually beneficial to other creatures and are used by humans for various purposes. Plant-like protists produce almost one-half of the oxygen on the planet through photosynthesis. Other protists decompose and recycle nutrients that humans need to live. For example, medicines made from protists are used in treatment of high blood pressure, digestion problems, ulcers, and arthritis. Hope That Helps!</em>

<em>From ~Itsbrazts~. Have a Great Day!</em>

6 0

3 years ago

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