help pls thx!!!!!!!
this is my last question i hope!

Answer:

boiling water - When water heats, the heat from the burner is transferred to the container, heating the water at the bottom. This hot water rises, creating a circular motion, as colder water descends to replace it.

Answer:

HIV attacks a specific type of immune system cell in the body. It's known as the CD4 helper cell or T cell. When HIV destroys this cell, it becomes harder for the body to fight off other infections.

Explanation:

Answer:

The scientist finds an equation that predicts how long the rainstrom will last.

Explanation:

I just answered it :)

Answer:

# ICSE board exam 2021

Explanation:

# ICSE board exam 2021

# ICSE board exam 2021

# ICSE board exam 2021

Answer:

A) q_o = 0.001 C

B) I = 0.001•e^(-t)

C) V_c = 1000e^(-t)

D) V_r = 1000e^(-t)

E) P = e^(-2t) watts

Explanation:

A) We are given;

Initial stored energy; U_o = 0.5 J

Capacitance; C = 1.0μF = 1 × 10^(-6) F

To find the charge, we will use the formula for energy in capacitors which is given by;

U = q²/2C

Thus, since we are dealing with initial energy, U is U_o and q is q_o

Making q the subject, we have;

q_o = √2CU_o

q_o = √(2 × 1 × 10^(-6) × 0.5)

q_o = 0.001 C

B) The charge as a function of time is expressed as;

q = q_o•e^(-t/RC)

Now the current is gotten by differentiating the charge function. Thus;

I = (q_o/RC)•e^(-t/RC)

Where;

R is Resistance = 1.0MΩ = 1 × 10^(6) Ω

C is capacitance = 1 × 10^(-6) F

(q_o/RC) is the initial current = 0.001/(1 × 10^(6) × 1 × 10^(-6))

(q_o/RC) = 0.001 A

Thus;

I = 0.001•e^(-t/(1 × 10^(6) × 1 × 10^(-6)))

I = 0.001•e^(-t)

C) Formula for potential difference across the capacitor is;

V_c = IR

I = 0.001•e^(-t)

R = 1 × 10^(6) Ω

Thus;

V_c = 1 × 10^(6) × 0.001•e^(-t)

V_c = 1000e^(-t)

D) Potential difference across the resistor will be the same as that across the capacitor because the resistor is connected in parallel to the capacitor.

Thus;

V_r = V_c = 1000e^(-t)

E) rate at which thermal energy is produced is basically the power.

Thus;

P = (V_r)²/R

P = (1000²e^(-2t))/1 × 10^(6)

P = e^(-2t) watts

Answer:

B . Second law

Explanation:

According to second law:

Net Force acting on the body produce acceleration. The magnitude acceleration of the body is directly proportional to net force and inversly proportional to the mass.

Mathematically:

                   a = [tex]\frac{F}{m}[/tex]

and

                   F = ma

So according to the given condition Waldo should use Second law.

Explanation:

[tex]let \: coefficient \: of \: friction \: be \: \gamma \\ from \: third \: law \: of \: solid \: friction \\friction \: force = \gamma \times normal \: reaction \\ F = \gamma R \\ but \: R = mg = 240N \\ \gamma = \frac{ F}{R} \\ \gamma = \frac{12}{240} \\ \gamma = \frac{1}{20} [/tex]

Answer:

supernova explosion or death of massive star

Explanation:

"Most black holes form from the remnants of a large star that dies in a supernova explosion."

Answer:

longer for less massive stars.

Explanation:

A star is a giant astronomical or celestial object that is comprised of a luminous sphere of plasma, binded together by its own gravitational force.

It is typically made up of two (2) main hot gas, Hydrogen (H) and Helium (He).

Some of the examples of stars are Canopus, Sun (closest to the Earth), Betelgeus, Antares, Vega etc.

Generally, the time taken for the collapse of an interstellar cloud fragment to the period (time) when a main-sequence star is given birth to, is usually longer for less massive stars.

This ultimately implies that, stars that are not so massive or big in size are transformed from interstellar cloud fragment to a main-sequence star is lesser.

Time taken from, when in interstellar cloud fragment first begins collapsing until it gives birth to a main-sequence star is longer for less massive stars.

The process of Interstellar cloud fragment results the development into the stars.

The formation of stars is takes place within the highly dense concentration of the interstellar gases and the dust. These interstellar gases and the dust forms the molecular or interstellar clouds.

Here, in these molecular clouds the gases are present like helium, CO, hydrogen in major amount. Now this clouds started to collapse due to their own weight and density, and the formation of star is started.

Here, the H₂ atoms, which are fused forms helium atoms, to their core to form the main-sequence star.

In general, the time it takes from when in interstellar cloud fragment first begins collapsing until it gives birth to a main-sequence star. The time required to form the main-sequence star is lesser than the star which has big size.

Hence, the time taken from, when in interstellar cloud fragment first begins collapsing until it gives birth to a main-sequence star is longer for less massive stars.

Learn more about the interstellar cloud fragment here;

https://brainly.com/question/1242059

Answer:

they employ front and Back defenses

Explanation:

there are the most positions in these types

Answer:

a = 640 m/s²

Explanation:

From work-kinetic energy principles,

The net force acting on the second object is the gravitational force and the electric force due to the first object.

So, the gravitational force on the mass is F₁ = Gm₁m₂/r² since m₁ = m₂ = m, U = -Gm²/r²

Also, the electric force on the charge is F₂ = kq₁q₂/r² since q₁ = q₂ = q, U = kq²/r²

The net Force F = ma

So, -F₁ + F₂ = F     (F₁ is negative since it is an attractive force in the negative x -direction and F₂ is positive since it is a repulsive force in the positive x- direction)

-Gm²/r² + kq²/r² = ma

ma = -Gm²/r² + kq²/r²

a = (-Gm²/r² + kq²/r²)/m

a = (-G + kq²/m²)m/r²

Since m = 0.250 kg, q = 4.00 μC = 4.00 × 10⁻⁶ C, r = 3.00 cm = 3.00 × 10⁻² m, G = 6.67 × 10⁻¹¹ Nm²/kg², k = 9 × 10⁹ Nm²/C² and a = acceleration of second mass.

Substituting the variables into the equation, we have

a = (m/r²)(-G + k(q/m)²)]

a = (0.250 kg/{3.00 × 10⁻² m}²)(-6.67 × 10⁻¹¹ Nm²/kg² + 9 × 10⁹ Nm²/C²(4.00 × 10⁻⁶ C/0.250 kg)²)

a = (0.250 kg/9.00 × 10⁻⁴ m)(-6.67 × 10⁻¹¹ Nm²/kg² + 9 × 10⁹ Nm²/C²(16 × 10⁻⁶ C/kg)²)]

a = (0.250 kg/9.00 × 10⁻⁴ m)(-6.67 × 10⁻¹¹ Nm²/kg² + 9 × 10⁹ Nm²/C²(256 × 10⁻¹² C²/kg²)]

a = (0.250 kg/9.00 × 10⁻⁴ m)(-6.67 × 10⁻¹¹ Nm²/kg² + 2304 × 10⁻³ Nm²/kg²  ]

a = (0.250 kg/9.00 × 10⁻⁴ m)(2.304 Nm²/kg²)

a = 0.576 Nm²/kg /9.00 × 10⁻⁴ m²

a = 0.064 × 10⁴N/kg

a = 64 × 10 N/kg)

a = 640 m/s²

Answer:

explanation

Explanation:

1 = C

2 = A

3 = D

4 = E

5 = B

Answer:

-33750 N

Explanation:

Use coulomb's law: [tex]\frac{k(q1)(q2)}{r^{2} } = \frac{(9x10^{9})(-5x10^{-6})(3x10^{-6})}{0.002^{2} } = -33750 N[/tex]

Answer:

AYE

Explanation:

Answer:

The speed of the plank relative to the ice is:

[tex]v_{p}=-0.33\: m/s[/tex]

Explanation:

Here we can use momentum conservation. Do not forget it is relative to the ice.

[tex]m_{g}v_{g}+m_{p}v_{p}=0[/tex] (1)

Where:

Now, as we have relative velocities, we have:

[tex]v_{g/b}=v_{g}-v_{p}=1.55 \: m/s[/tex] (2)

v(g/b) is the speed of the girl relative to the plank

Solving the system of equations (1) and (2)

[tex]45v_{g}+168v_{p}=0[/tex]

[tex]v_{g}-v_{p}=1.55[/tex]

[tex]v_{p}=-0.33\: m/s[/tex]

I hope it helps you!      

Answer:

by radiation

by heating

electrically

mechanically

Answer:

a) [tex]\vec{d} =B-A[/tex]

b) [tex]I=\frac{B*v*d*\sin 90 \textdegree}{R}[/tex]

c) [tex]v \approx 0.6m/s[/tex]

Explanation:

From the question we are told that

Magnetic field strength [tex]B=3.6T[/tex]

Distance traveled [tex]d=7m[/tex]

Mass [tex]m=4.7 kg[/tex]

Resistance [tex]r=8.2 ohm[/tex]

Gravitational acceleration [tex]g=9.8m/s^2[/tex]

[tex]\theta =90 \textdegree[/tex] Because of perpendicularity

a)

Generally the direction of the current will be given as

[tex]\vec{d} =B-A[/tex]

Because it opposes increases of magnetic flux

b)

Generally the equation for induced EMF [tex]E[/tex] is mathematically given as

[tex]E=B*v*d*\sin \theta[/tex]

[tex]E=B*v*d*\sin 90 \textdegree[/tex]

Generally the equation for induced current [tex]I[/tex] is mathematically given as

[tex]I=E/R[/tex]

[tex]I=\frac{B*v*d*\sin 90 \textdegree}{R}[/tex]

c)

Generally the the equation for force F at terminal speed is mathematically given as

[tex]F=mg[/tex]

[tex]mg=B*I*d*\sin 90 \textdegree[/tex]

[tex]mg=B*(\frac{B * v * d }{R}) *d[/tex]

[tex]v=\frac{m*g*R}{B^2*D^2}[/tex]

[tex]v=\frac{4.7*9.8*8.2}{3.6^2*7^2}[/tex]

[tex]v=0.59475m/s[/tex]

[tex]v \approx 0.6m/s[/tex]

1 a. Spherical Mirror

2. Both A and B

3. Concave mirror

4.Inwards

5. Pole.

These are your answer. You can mark me Brainliest. Thanks.

hope it helps you have a good day

Explanation:

spherical mirror

both A and B

inwards

pole

Answer:

In my opinion, ''A" would be the longest wavelength.

Answer:

354

Explanation:

Answer:

The initial speed of bullet is "164 m/s".

Explanation:

The given values are:

mass of bullet,

[tex]m'=9.00 \ g[/tex]

or,

    [tex]=0.009 \ kg[/tex]

mass of wooden block,

[tex]m=1.20 \ kg[/tex]

speed,

[tex]s=0.390 \ m[/tex]

Coefficient of kinetic friction,

[tex]\mu=0.20[/tex]

As we know,

The Kinematic equation is:

⇒  [tex]v^2=u^2+2as[/tex]

then,

Initial velocity will be:

⇒  [tex]u=v^2-2as[/tex]

        [tex]=v^2-2 \mu gs[/tex]

On substituting the given values, we get

⇒  [tex]u=\sqrt{0-2\times 0.20\times 9.8\times 0.390}[/tex]

       [tex]=\sqrt{-1.5288}[/tex]

       [tex]=1.23 \ m/s[/tex]

As we know,

The conservation of momentum is:

⇒  [tex]mu=m'u'[/tex]

or,

⇒ Initial speed, [tex]u'=\frac{mu}{m'}[/tex]

On substituting the values, we get

⇒                            [tex]=\frac{1.20\times 1.23}{0.009}[/tex]

⇒                            [tex]=\frac{1.476}{0.009}[/tex]

⇒                            [tex]=164 \ m/s[/tex]                              

Answer:

Gases - Water vapor, Nitrogen, Oxygen etc. Describe what happens to air pressure as you rise upwards in the atmosphere. What causes this change in air pressure? As altitude increases, air pressure will decrease As altitude increases the gas molecules that make up the air spread further apart

Answer: As you rise upwards in the atmosphere, air pressure decreases

Explanation: Because there are fewer molecules in the air, the air has a lower density, which results in a drop in air pressure. At different altitudes, the air is not the same. The area close to the earth is denser. As we rise, it continues to thin out. As a result of more air nearby, there is also increased air pressure. The weight and pressure of the air also continue to reduce as the volume of air does.

Answer:

Z  = (R^2 + X^2)^1/2

At the resonant frequency, the quantity X equal zero and

w L - 1 / (w * C) equals zero where w is omega the angular frequency

Answer:

fffffgggggggggggggghhh

The sun is made up mostly of  plasma material. Option D

Plasma is considered the fourth state of matter, distinct from gases, liquids, and solids. It is a highly ionized gas consisting of charged particles, including electrons and ions. The sun is primarily composed of plasma due to the extremely high temperatures and intense energy present in its core.

The sun's core has a temperature of about 15 million degrees Celsius (27 million degrees Fahrenheit), which is hot enough to strip electrons from atoms, creating a plasma state. The high temperature and pressure cause hydrogen atoms to undergo nuclear fusion, resulting in the release of vast amounts of energy in the form of light and heat.

This fusion process involves the conversion of hydrogen nuclei (protons) into helium nuclei, releasing enormous energy in the process. The intense heat and pressure within the sun's core sustain this fusion reaction, powering the sun and providing the energy that is radiated out into space as sunlight.

Plasma is an electrically conductive state of matter, meaning it can carry electric currents. The sun's plasma exhibits complex dynamics, including the generation of magnetic fields, solar flares, and coronal mass ejections.

In summary, the sun is primarily composed of plasma material due to the extreme temperatures and intense energy within its core. The plasma state allows for nuclear fusion to occur, releasing the immense energy that sustains the sun's radiative output.

Option D

For more such question plasma material visit:

https://brainly.com/question/30475382

#SPJ8

Answer:

the required current is 0.12 A

Option b) 0.12 A is the correct answer

Explanation:

Given the data in the question,

to determine the current needed in the wire, we use the following relation;

B = μ₀n[tex]I[/tex]

[tex]I[/tex] = B / μ₀n

where μ₀ is the magnetic constant   ( 4π × 10⁻⁷ T.m/A )

n is the number of turns ( 1 / 1mm[tex]\frac{10^{-3}m}{1 mm}[/tex]) = 1000 m⁻¹

B is magnitude ( 150μT ( [tex]\frac{10^{-6}m}{1uT}[/tex]) )

so we substitute

[tex]I[/tex] =  [ 150μT ( [tex]\frac{10^{-6}m}{1uT}[/tex]) ] / [ ( 4π × 10⁻⁷ T.m/A ) × 1000 m⁻¹ ]

[tex]I[/tex] =  [ 0.00015 ] / [ 0.00125 ]

[tex]I[/tex] = 0.12 A

Therefore, the required current is 0.12 A

Option b) 0.12 A is the correct answer

Answer:

110N north west

Explanation:

.........

If three forces F1 = 20N, 300NE, F2 = 50N along W, F3 = 40N 500NW act on a body. The resultant in magnitude and direction  is 110N north west

Force is a  quantitative parameter and it is an interaction between two physical bodies such as an object and its environment, there are different types of forces in nature.

it can be  defined as pushing or pulling of any object resulting from the object’s interaction or movement, without force the objects can not move

If an object in moving state the it will be either static or motion, the position of the object will only be changed if it is pushed or pulled and The external push or pull upon the object called as Force.

The contact force types  are  Spring Force, Applied Force, Air Resistance Force, Normal Force, Tension Force, Frictional Force

Non-Contact forces are occur from a distance  such as Electromagnetic Force, Gravitational Force, Nuclear Force

For more details Force,  visit

brainly.com/question/13691251

#SPJ2