why a mirror is good for seeing objects

Answer: ARE YOU DOING PRIMAVERA?!? PLEASE I KNOW YOU ARE I CANT DO PHYSICS-

Explanation:

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The pigeon final position displacement vector represented as , [tex]-2.9i-4.8j[/tex]

Given that Pigeon walks 4.0 m West then  2.5 m North then  1.1 m east and then 7.3 m south.

A diagram is attached below which describe the above situation.

In attached diagram, Distance DO represent the displacement.

From Diagram, it is observed that final position D of Pigeon is 4.8 m away from x axis and 2.9 m away from y axis.

Thus, Displacement vector represented as  , [tex]-2.9i-4.8j[/tex]

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Answer:

D

Explanation:

Answer: 519.4 N

Explanation:

53 kg x 9.8 m/s = 519.4 N

If a 53 kg Boulder falls off a cliff, the force with which it will hit the ground is 519.4 N.

A force is an effect that can alter an object's motion according to physics. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.

Given in the question  a 53 kg Boulder falls off a cliff, what is the force with which it will hit the ground,

force = mass * acceleration due to gravity

         = 53 kg x 9.8 m/s

         = 519.4 N

If a 53 kg Boulder falls off a cliff, the force with which it will hit the ground is 519.4 N.

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Answer:

The maximum height of Phran stone is four time that of Phred stone

Explanation:

From the question we are told that

   The initial velocity of Phred stone is  u

    The initial velocity of  Phran stone is  2u

Generally from kinematic equations

       [tex]v^2 = u^2 + 2(-g)h[/tex]

Here the negative sign shows that the direction of the stone is against gravity

At the maximum height v which is the final velocity of the stone is zero  

So

      [tex]0 = u^2 - 2gh[/tex]

So for Phred stone the height attained is  

=>   [tex]h_1 = \frac{u^2}{2g}[/tex]

For  Phran stone the height attained is  

=>   [tex]h_2 = \frac{(2u)^2}{2g}[/tex]

=>    [tex]h_2 = \frac{4u^2}{2g}[/tex]

=>    [tex]h_2 = 4 h_1[/tex]

Hence the maximum height of Phran stone is four time that of Phred stone

Answer:

144

Explanation:

18 multiplied by 8 equals 144. Hope I helped!  εїз

Answer:

The answer is 144.

Explanation:

18X8=144

Answer:

15km/h

Explanation:

Time taken to complete 30km/h=2 hours=15km/h hence the average speed is 15km/h.

Answer:

b

Explanation:

i guessed annd got it right

Answer:

Reaction B involves a greater change and a change in element identity.

Explanation:

Answer:

See the answers below

Explanation:

In this problem, we must be clear about the concept of weight. Weight is defined as the product of mass by gravitational acceleration.

We must be clear that the mass is always preserved, that is, the mass of 15 [kg] will always be the same regardless of the planet where they are.

[tex]W=m*g[/tex]

where:

W = weight [N] (units of Newtons)

m = mass = 15 [kg]

g = gravity acceleration [m/s²]

Since we have 9 places with different gravitational acceleration, then we calculate the weight in each of these nine places.

Mercury

[tex]w_{mercury} = 15*3.8\\w_{mercury}= 57 [N]\\[/tex]

Venus

[tex]w_{venus}=15*8.8\\w_{venus}= 132 [N][/tex]

Moon

[tex]w_{moon}=15*1.6\\w_{moon}=24[N][/tex]

Mars

[tex]w_{mars}=15*3.7\\w_{mars}=55.5 [N][/tex]

Jupiter

[tex]w_{jupiter}=15*23.1\\w_{jupiter}= 346.5[N][/tex]

Saturn

[tex]w_{saturn}=15*9\\w_{saturn}=135[N][/tex]

Uranus

[tex]w_{uranus}=15*8.7\\w_{uranus}=130.5[N][/tex]

Neptune

[tex]w_{neptune}=15*11\\w_{neptune}=165[N][/tex]

Pluto

[tex]w_{pluto}=15*0.6\\w_{pluto}=9[N][/tex]

Answer:33s

Explanation:

Answer: 3.3 seconds

Explanation:

I just did it

Answer:

I = 2 [amp]

Explanation:

To solve this problem we must use ohm's law, which tells us that the voltage is equal to the product of the current by the resistance.

The resistances in the diagram are connected in series, in this way the total resistance will be equal to the algebraic sum of the resistivity.

R = R1 + R2

R = 3 + 2

R = 5 [ohm]

Now, using ohm's law we have:

V = I*R

where:

V = voltage = 10 [V]

I = current [amp]

R = resistance = 5 [ohm]

I = V/R

I = 10/5

I = 2 [amp]

Answer:

260 km/h

Explanation:

Motion is said to be relative when the motion observed by the observer depends on the location (frame) of the observer.

When two objects are moving in opposite directions, the relative motion is obtained by subtraction.

Hence  the plane is moving at (285 - 25) km/h giving 260 km/h

Answer:

The mass of the ice produced is approximately 0.00212 kg

Explanation:

The given parameters are;

The temperature at which the air changed from water to ice = 0°C

The internal energy change of the water as it froze = 0.7 kJ

The specific latent heat of fusion of water = 330 kJ/kg

Given that the change in internal energy causes the water to change state, from the principle of energy conservation, we have;

The latent heat of fusion = The change in internal energy of the water as it froze

∴ The latent heat of fusion [tex]\Delta H^{\circ}_{fus}[/tex]  = 0.70 kJ

The formula for the latent heat of fusion, [tex]\Delta H^{\circ}_{fus}[/tex] = Mass × The specific latent heat of fusion, [tex]L^{\circ}_f[/tex]

Therefore, for the water, we have;

0.7 kJ = m × 330 kJ/kg

m = 0.7 kJ/(330 kJ/kg) ≈ 0.00212 kg

The mass, m, of the ice produced ≈ 0.00212 kg.

Answer:

Unit

Explanation:

The reference standard used for the measurement of physical quantity is called the unit of that quantity.

Most units follow an agreed system of expressing quantities across all instances of such quantity.

Explanation:

where is the option of the Question

Answer:

Please find the answer in the explanation.

Explanation:

The variable/s you can manipulate in the simulation to make all the items get the same proximate values for their acceleration will be the variable final velocity. Since all of them have zero initial velocity, the acceleration will tend to zero if they have a constant velocity.

If the final velocity is also zero or approximately equal to zero, that means the velocity is constant. And whenever there is constant velocity, the acceleration will be equal to zero.

Also, if the final velocity of all the parameters are very closed, they will surely have approximately same acceleration.

The variable which can be manipulated in the simulation will be the final

velocity.

The table shows all of them having the same initial velocity which is zero,

then the final velocity will have to be varied in order to get the same

proximate values for their acceleration.

Acceleration is the rate of change of velocity with time and when the velocity

is constant or equal to zero, the acceleration will be equal to zero.If the final

velocity of all the parameters are very close in value , then they will have

proximate values for acceleration.

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Answer:

B) boiling point

Explanation:

The movement of the particles causes the shape of the liquid to change. The liquid will flow and fill to the lowest part of the container, in the shape of the container

But the volume does not change. The limited amount of space between the particles means that the liquid has only very limited compressibility.

Answer:

A) Density

Explanation:

Answer:

33 Newton upwards to get a net force of zero.

Answer:

The answer is 33 newtons with a net force of 0

Explanation:

Answer:

8n

Explanation:

Answer:

Search it

Explanation:

its on it

Answer:

3.

Force(f) =2000N

Distance (d) =10m

Time(t)=50 sec

We know,

P=W/t

=f×d/t

=2000×10/50

=400 watt

4.

Force(f) =30N

Distance (d) =10 m

Time(t) =5 sec

We know,

P=w/t

=f×d/t

=30×10/5

=60 watt

4000 ÷ 8 = 500

Its 500 m/s as shown in the calculation above.

Explanation:

Oxygen has an atomic number of 8 with 2 electrons in its innermost shell (s orbital) and 6 remaining electrons in its outermost shell.

The electronic configuration of the oxygen element will therefore be expressed as;

1s²2s²2p⁴

Since we are to find the valence electron configuration of oxygen, this means we are going to consider only electrons in the outermost shell. The outermost shell of oxygen only contains 6electrons. The electronic configuration will be;

2s²2p⁴ (ignoring the innermost electrons)

Comparing with As^B2p^C

we will have;

As^B = 2s²

A = 2, B = 2

2p^C = 2p⁴

p^c = p⁴

C = 4

Hence A = 2, B = 2 and C = 4

The oxygen ion is represented as O₂²⁻. Therefore the charge of an oxygen ion is -2

Answer:

a=2

b=2

c=4

-2

Explanation:

Answer:

The air temperature at the tropopause is - 79 °C

Explanation:

We know that a station near the equator has a surface temperature of 25°C

Vertical soundings reveal an environmental lapse rate of 6.5 °C per kilometer.

The tropopause is encountered at 16 km.

In order to find the air temperature at the tropopause we are going to deduce a linear function for the temperature at the tropopause.

This linear function will have the following structure :

[tex]f(x)=ax+b[/tex]

Where ''[tex]a[/tex]'' and ''[tex]b[/tex]'' are real numbers.

Let's write [tex]T(x)[/tex] to denote the temperature '' T '' in function of the distance

'' x '' ⇒

[tex]T(x)=ax+b[/tex]

We can reorder the function as :

[tex]T(x)=b+ax[/tex] (I)

Now, at the surface the value of ''[tex]x[/tex]'' is 0 km and the temperature is 25°C so in the function (I) we write :

[tex]T(0)=25=b+a(0)[/tex] ⇒ [tex]b=25[/tex] ⇒

[tex]T(x)=25+ax[/tex] (II)

In (II) the value of ''[tex]a[/tex]'' represents the change in temperature per kilometer.

Because the temperature decrease with the height this number will be negative and also a data from the question ⇒

[tex]T(x)=25-(6.5)x[/tex] (III)

In (III) we deduced the linear equation. The last step is to replace by [tex]x=16[/tex] in (III) ⇒

[tex]T(16)=25-(6.5)(16)=-79[/tex]

The air temperature at the tropopause is - 79 °C

Answer:

U = 18,785 J

Explanation:

Elastic Energy

Elastic energy is energy stored in an object due to a force that temporarily changes its shape, such as shrinking or stretching.

The elastic energy can be calculated as follows:

[tex]\displaystyle U=\frac{1}{2}k(\Delta x)^2[/tex]

Where k is the spring constant, and \Delta x is the change in the size of the spring.

The bungee cord stretches \Delta x =17 m, and k=130 N/m, thus:

[tex]\displaystyle U=\frac{1}{2}130(17)^2[/tex]

U = 18,785 J

Potential energy = m · g · h

-- When you held the ball at 2.0 meters above the floor, it had

(0.5 kg) · (9.8 m/s²) · (2.0 m) = 9.8 Joules of potential energy.

-- After it bounced and went back up as high as it could, it was only 1.8 meters above the floor.  Its potential energy was

(0.5 kg) · (9.8 m/s²) · (1.8 m) = 8.82 Joules

-- Between the drop and the top of the bounce, it lost

(9.8 - 8.82) = 0.98 Joule .

-- The energy was lost when the ball hit the floor.  During the hit, 0.98 joule of kinetic energy turned to thermal energy, which slightly heated the ball and the floor.

Answer:

a)  y_total = 575.4 m , b)   t_total = 22.56 s , c)  v = 106.20 m

Explanation:

a) We can solve this exercise using the scientific relations

Let's find the height reached while the engines are running

         v₁ = v₀ + a t

         v₁ = 62.3 + 4.30 3.73

         v₁ = 78.339 m / s

in this time it rose

        y₁ = v₀ t₁ + ½ a t₁²

        y₁ = 62.3 3.73 + ½ 4.30 3.73²

         y₁ = 262.29 m

At this moment the engines are turned off and the rocket continues in a vertical launch, suppose that the acceleration of gravity is constant in this path

        v₂ = v₁ 2 - 2 g y₂

at maximum height the velocity is zero (v₂ = 0)

        y₂ = v₁ 2 / 2g

        y₂ = 78.339 2/2 9.8

        y₂ = 313.11 m

the total height is

       y_total = y₁ + y₂

       y_total = 262.29 + 313.11

       y_total = 575.4 m

b) the time the rocket is in the air is

       t_total = t₁ + t₂

where t₂ is the time after the engines have shut down

       y = y₁ + v₁ t₂ - ½ g t₂²

      y = 0

      0 = 262.29 + 78.339 t₂ - ½ 9.8 t₂²

      t₂² - 15.99 t₂ - 53.53 = 0

      t₂ = [15.99 ±√ (15.99² +4  53.53)] / 2

      t₂ = [15.99 ± 21.67] / 2

      t₂´ = 18.83 s

      t₂´´ = -2.84 s

since the time must be a positive quantity the correct result is t2 = 18.83 s, the total time in the air is

      t_total = 3.73 + 18.83

      t_total = 22.56 s

c) the speed when it hits the ground

We can perform this calculation starting with the maximum height y = 575.4 m where it has zero initial velocity (vo = 0)

      v² = v₀² + 2 g y

      v = √ 2gy

       v = √ (2 9.8 575.4)

       v = 106.20 m

Answer:

When frequency increases more wave crests pass a fixed point each second. That means the wavelength shortens. So, as frequency increases, wavelength decreases. The opposite is also true—as frequency decreases, wavelength increases.