write a reaction equation to show HCO3 acting as an acid​

Answer:

a) Watt is a derived unit because it's not a “base unit.”

b) The atomic clock is suitable for measuring time because natural atomic oscillations happen at a higher frequency and as a result they are more stable.

c) There is fluctuation in time measured by a pendulum clock because the pendulum rod changes in length slightly with changes in temperature, causing changes in the rate of the clock. An increase in temperature causes the rod to expand, making the pendulum longer, so its period increases and the clock loses time.

D) The weight of an object is more at pole and less at equator of the earth because the distance of the pole is less than the distance of the equator from the centre of the earth.

e) The weight of an object on the moon is about one-sixth the weight it would have on the earth because the moon's gravitation force is determined by the mass and the size of the moon. Hence, the weight of an object on the moon is 1/6th its weight on the earth.

Answer: Rods

Explanation:

The rod cells in the retina are the reason we are able to see at night and in dim light. They exist on the edges of the retina which is why they are also very useful for the peripheral vision of a human.

Rod cells number over 90 million in the eyes and although very useful for seeing in dimmer light, they are not very useful for color vision which is why humans see less colors in the dark.

Answer:

I believe in aliens but I do not think everyone should. I started to believe in aliens since the US government said they would be taking extraterrestrial life seriously. They will be in our lives sooner or later, so we shouldn't be ignoring their presence. I believe them because surveys show that nearly half of Americans believe that aliens have visited the Earth, either in the ancient past or recently. That percentage has been increasing. Belief in alien visitation is greater than belief that Bigfoot is a real creature, but less than belief that places can be haunted by spirits. Also there have been a lot of UFO sightings, and a Navy Jet has a video of that as well. These small things is just hard to ignore, and they make me and hopefully others believe in aliens.

Answer:

Let the initial charges be q1 and q2 respectively.

After they come in contact, the charges are rearranged such that they acquire same charge.

let us say that charge on each of them is Q.

They are again brought apart at a distance of 0.9 m. Hence, the force between them will be given as

F = kQ2 / r2

0.025 = (9×109 x Q2) / 0.92

Q2 = 0.025 x 0.92 / 9×109

Q = 1.5 x 10-6 C

Explanation:

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The drawing shows the couple acting on a tire wrench is missing and so i have attached it.

We are to find an expression for the torque when the axis is perpendicular to the tire and passes through the points A, B & C

Answer:

Point A: τ = Fl

Point B: τ = 0

Point C: - Fl

Explanation:

Formula for torque is;

τ = F × d

Where;

F is perpendicular force

d is distance.

Thus;

> At point A, it means we are taking torque about point A and so we have;

τ = (-F × 0) + (F × L)

τ = Fl

> At point B, it means we are taking torque about point B and so we have;

τ = (-F × L/2) + (F × L/2)

τ = -(FL/2) + (FL/2)

τ = 0

> At point C, it means we are taking torque about point C and so we have;

τ = (-F × L) + (F × 0)

τ = -FL

Answer:

Nuclear fusion in the Sun's core causes the release of tremendous amounts of energy that leads to very high temperatures and pressure which is much hotter and higher than the temperature and pressure at the exterior surface of the Sun causing the particles in the inner core region to push outwards towards the Sun's surface

Explanation:

Such asSuch ToSuch aSuch as طHow do I send the answer to the question?OkI don't know how to use this program

Answer:

MOMENTUM = 40kg ms-¹

hope it helps

have a nice day

Answer:

the efficiency of the machine is 100%

Explanation:

Given;

load, L = 750 N

length of the lever, L = 2 m

effort applied, E = 250 N

Position of the load from the fulcrum,  = 50 cm

                                     50cm

     0↓--------------------------Δ-------------------------------↓---------200 cm

    750 N                                       x cm                 250 N

Apply the principle of moment;

750(50) = 250(x)

x = (750 x 50) / (250)

x = 150 cm

the distance of the effort = 150 cm = 1.5 m

the distance of the load = 50 cm = 0.5 m

The velocity ratio of the machine = 1.5/0.5

                                                        = 3

The mechanical advantage of the machine is calculated as;

M.A = Load/effort

M.A = 750 / 250

M.A = 3

The efficiency of the machine is calculated as;

E = (M.A / V.R) x 100%

E = (3/3) x 100% = 100%

Therefore, the efficiency of the machine is 100%

Answer:

2 cm.

Explanation:

Please see attached photo for diagram.

In the attached photo, y is the distance from the pivot to which the 25 g is placed.

The value of y can be obtained as follow:

Clockwise moment = 5 × 10

Anticlock wise moment = y × 25

Anticlock wise moment = Clockwise moment

y × 25 = 5 × 10

y × 25 = 50

Divide both side by 25

y = 50/25

y = 2 cm

Thus, the distance is 2 cm

Answer:

The sun uses hydrogen for nuclear fusion.

Answer:

Hydrogen

Explanation:

Answer:

C. 9.9 cm

Explanation:

The location of the object, u = 14 cm

The location of the image, v = 5.8 cm

The focal length of the mirror, f = Required

The mirror formula for a convex mirror is given as follows;

[tex]\dfrac{1}{u} -\dfrac{1}{v} = -\dfrac{1}{f}[/tex]

Therefore, we get;

[tex]\dfrac{1}{14 \ cm} -\dfrac{1}{5.8 \ cm} =- \dfrac{41}{406 \ cm} = -\dfrac{1}{f}[/tex]

Therefore;

[tex]f = \dfrac{406 \ cm}{41} \approx 9.9 \ cm[/tex]

The focal length of the mirror, f ≈ 9.9 cm

Answer:

-4000 N

Explanation:

newton second law F=ma

m=1000kg

vi=20m/s

vf=0

d=50 m

vf^2=vi^2+2ad

0=20^2+2a×50

100 a= -400

a= -4 m/S2

F=ma = 1000×-4 = -4000 N

Answer:

ocean wave

hope it helped you

Explanation:

study of motion of an object ...plzz if anyone knies the correct meaning of it ..do comment

Answer:

the brightest found are Blue - White with

Explanation:

The energy emission of objects increases with their temperature, specifically Wien described the process in an expression

          [tex]\lambda_{maximum}[/tex] T = 2,898 10⁻³

With this expression we can find the temperature of the stars by the color they emit.

Specifically the Sun has a color of 550 nm which corresponds to 5400K

bright stars have a BLUE color corresponding to 7500K

the brightest found are Blue - White with a temperature of 20000K

Answer:

Acceleration is 1.2 m/s^2.

Explanation:

initial velocity, u = 0

distance, d = 60 m

time, t = 10 s  

Let the acceleration is a.

use second equation of motion

[tex]s= u t +0.5 at^2\\\\60 = 0 + 0.5 \times a \times 10\times 10\\\\a = 1.2 m/s^2[/tex]

Now according to the Newton's second law

Force = mass x acceleration

Let the mass is m.

F = m x 1.2 = 1.2 m Newton  

Answer:

Hello. You did not provide the video to which the question refers, however, given the context of your question, we can consider that the forces acting on the wheel are the weight of the wheel, the tension that this weight promotes on the rope and the normal force of the axle.

Explanation:

According to the context of the question, we can see that the wheel is being pulled by a rope. The weight of the wheel is the first force that acts on it, promoting resistance to the impulse that the rope promotes on the wheel. When this wheel is pulled by the rope, the weight of the wheel creates tension in the rope, which stretches and becomes tensioned in response to this force. However, this tension is also a force acting on the wheel, as is the normal force on the axis between these two elements.

Answer:

Value closest to 1

Explanation:

It is described from the scenario above that ice cream sales decreases as the outside temperature increases, hence showing a strong relationship between both variables (icream sales and temperature). The correlation Coefficient is a metric used in regression modeling to depict the strength of relationship between two variables, (The dependent and independent variables). Correlation Coefficient ranges from (-1 to +1). With values close to 1 or - 1. Also the positive and negative signs are used to show the type of relationship between the variables. If an increase in variable A leads to a decrease in variable B, then we have negative correlation (-) ; while an increase or decrease in both variables depicts a positive correlation. The most likely correlation Coefficient for the study above will be a positive value which is close to 1 since the relationship is described as strong.

Answer:

F = 9.177*10^-9N

Explanation:

Gravitational force between the two bodies is expressed as;

F = GMm/r²

Given tha

M = 55kg

m = 10kg

r = 2m

G = 6.67408 × 10-11 m³ kg-1 s-2

Substitute;

F = GMm/r²

F = 6.67408 × 10-11*55*10/2²

F = 3,670.744× 10-11/4

F = 9.177*10^-9N

26. D. crushing the sugar cube and dissolving it in water.

27. A. atom

28. B. molecule

29. B. plum pudding model of Joseph John Thomson

30. B. He used cathode ray tubes which showed that all atoms contain tiny negatively charged subatomic particles or electrons

31. D. protons and neutrons are relatively heavier than electrons.

Answer:

T₂ = 305.17 K

Explanation:

Given that,

Heat, Q = 6000 J

Mass, m = 200 gram

Initial temperature, T₁ = 25° C

We need to find its final temperature. Let it is T₂.

We know that,

[tex]Q=mc\Delta T[/tex]

Where

c is the specific heat of water, c = 4.18 J/g°C

So,

[tex]6000=200\times 4.18\times (T_2-298)\\\\\dfrac{6000}{200\times 4.18}=(T_2-298)\\\\7.17=(T_2-298)\\\\7.17+298=T_2\\\\T_2=305.17\ K[/tex]

So, the final temperature is equal to 305.17  K.

Answer:

[tex]\triangle \phi=461.5rad[/tex]

Explanation:

From the question we are told that:

Silt width [tex]w=0.15=>0.1510^{-3}[/tex]

Wavelength [tex]\lambda=462nm=462*10^{-9}[/tex]

Angle [tex]\theta=26.9[/tex]

Generally the equation for Phase difference is mathematically given by

[tex]\triangle \phi=\frac{2 \pi}{\lambda}(\frac{wsin\theta }{2})[/tex]

[tex]\triangle \phi=\frac{2 \pi}{462*10^{-9}}(\frac{0.1510^{-3}*sin 26.9 }{2})[/tex]

[tex]\triangle \phi=461.5rad[/tex]

[tex]\triangle \phi=146.89\pi[/tex]

Answer:

The measurement of first cylinder is more accurate.(A)

Explanation:

The least possible error higher will be accuracy.

Answer:

519.62 m/s

Explanation:

Applying,

v = √(T/m').............. Equation 1

Where v = velocity of the wave, T = Tension on the string, m' = mass per unit length of the string

From the question,

Given: T = 1350 N, m' = 0.005 kg/m

Substitute these values into equation 1

v = √(1350/0.005)

v = √(270000)

v = 519.62 m/s

Question

Using atomic weight, crystal structure, and atomic radius data tabulated inside the front cover of thebook, compute the theoretical densities of aluminum (Al), nickel (Ni), magnesium (Mg), and tungsten (W), and thencompare these values with the measured densities listed in this same table. The c/a ratio for magnesium is 1.624.

Explanation:

Answer:

To explore the other planets, the satellite must have the velocity more than the escape velocity.

Explanation:

The minimum velocity required by any object to escape from the earth gravitational pull is called the escape velocity.

The escape velocity for any planet depends on the mass of planet and radius of planet. It does not depends on the mass of object. The escape velocity is same for any mass for a particular planet.

So, to explore the other planets, the satellite must have the velocity more than the escape velocity.

Answer:

True.

Explanation:

The velocity vector is constant in magnitude but changing in direction. Because the speed is constant for such a motion, many students have the misconception that there is no acceleration. ... But the fact is that an accelerating object is an object that is changing its velocity.

Answer:

$900

Explanation:

Step 1: Our output value is 9000.

Step 2: We represent the unknown value with x.

Step 3: From step 1 above,$9000=100\%$

Step 4: Similarly, x=10%

Step 5: This results in a pair of simple equations:

$9000=100

Step 6: By dividing equation 1 by equation 2 and noting that both the RHS (right hand side) of both

equations have the same unit (%); we have

\frac{9000}{x}=\frac{100\%}{10\%}

Step 7: Again, the reciprocal of both sides gives

\frac{x}{9000}=\frac{10}{100}$

\Rightarrow x=900$

Therefore, $10\%$ of $9000$ is $900$

unknown value with x

step 1 above,$9900=100%

similarly ,x=10%

Answer:

We need standard unit for measurement to make our judgement more reliable and accurate. For proper dealing, measurement should be same for everybody. Thus there should be uniformity in measurement. For the sake of uniformity we need a common set of units of measurement, which are called standard units.