In the figure calculates the acceleration of the block friction not today

Carbon dioxide is the most abundant greenhouse gas in the atmosphere.

Answer:C

Explanation:

Carbon dioxide is the most abundance greenhouse gas in The atmosphere.

Answer:electric current can be generated by moving a metal wire through a magnetic field .electric current can also be produced by batteries

Explanation:

electric current can be generated by moving a metal wire through a magnetic field.this method is applicable in electric generators.

Electric current can also be generated by connecting metal wires to batteries.

Answer:

Explanation:

Given that,

h(t) = -9.8t² / 2 + 125t + 500

for t > 0.

At t = 0, the rocket is at height h = 500m, at a velocity of Vo = 125m/s.

We want to find the maximum height reached by rocket

Using mathematics maxima and minima

let find the turning point when dh/dt = 0

dh/dt = -9.8t + 125

dh / dt = 0 = -9.8t + 125

9.8t = 125

t = 125 / 9.8

t = 12.76s

Let find the turning point to know if this time t = 12.76 is maximum or minimum point

Let find d²h / dt²

d²h / dt² = -9.8

Since, d²h/dt² < 0, then, at t = 12.76s is the maximum points.

Then, the maximum height reached is

h =  -9.8t² / 2 + 125t + 500

h =  -9.8(12.76)² / 2 + 125(12.76) + 500

h = -797.80 + 1595 + 500

h = 1297.2 m

The maximum height reached is 1297.2 m

From the attachment, the maximum height is 1297.2m at t = 12.76sec.

Comment, the result are the same for both the analysis aspect and the graphical aspect.

Answer:

2.10 V

Explanation:

To find the potential difference across the ends of the bar, you take into account that when the bar moves with speed v, in a constant magnetic field, the charges in the wire feels a magnetic force that separate the opposite charges, generating an induced potential difference given by the following formula:

[tex]\epsilon=vBL[/tex]   (1)

v: speed of the bar = 11.5 m/s

B: magnitude of the magnetic field = 1.22 T

L: length of the bar = 15.0cm = 0.15m

You replace the values of v, B and L in the equation (1):

[tex]\epsilon=(11.5m/s)(1.22T)(0.15m)=2.10\ V[/tex]

hence, the induced potential difference is 2.10 V

Answer:

Explanation:

Let the bullets speed be V .

Kinetic energy = 1/2 mV² where m is mass of bullet

This energy is converted into heat Q which raises the temperature of target by Δ T .

Q = mc Δ T  , m is mass , c is specific heat and Δ T is rise in temperature .

heat absobed by bullet

= .0075 x 130 x .040

= .039 J

heat absorbed by block of wood

= 17.5 x 1700 x .04

= 1190 J

Total heat absorbed

= 1190.039 J

So kinetic energy = heat absobed

= 1/2 x .0075 x V² = 1190.039

V² = 317343.73

V  = 563.33 m /s

Answer:

C. is always perpendicular to the surface of the conductor

Explanation:

On a charged conductor , electric charge is uniformly distributed on its surface . The lines of forces are also uniformly  distributed on all directions . They repel each other so they emerge perpendicular to the surface so that they do nor cut each other and at the same time they remain at maximum distance from each other.

Answer:

Question 3: 2.25 watts

Question 4: 405 joules

Explanation:

question 3:

Current =0.5 amps

Voltage =4.5 volts

Power= current x voltage

Power=0.5 x 4.5

power=2.25 watts

Question 4

Current =0.5 amps

Voltage =4.5v

Time=3 minutes

Time =3x60

Time =180 seconds

Energy=current x voltage x time

Energy =0.5 x 4.5 x 180

Energy =405 joules

Answer:

The speed of Lilac is 0.399c.

Explanation:

The size of spaceship Lilac measured at the rest position = 721 m  

The length of  Lilac when it passes Earth = 661 m

Below is the calculation for speed at which Lilac is moving.

Here, L, is the length of spaceship when it passes the earth.

[tex]L_{0}[/tex] is the length of spaceship measured at rest.

V is the speed.

[tex]L = L_{0}\sqrt{1-\frac{v^{2}}{c^{2}}} \\[/tex]

[tex]1-\frac{v^{2}}{c^{2}} = \left ( \frac{L}{L_{0}} \right )^{2} \\[/tex]

[tex]\frac{v}{c} = \sqrt{1-\left ( \frac{L}{L_{0}} \right )^{2}} \\[/tex]

[tex]\frac{v}{c} = \sqrt{1-\left ( \frac{661}{721} \right )^{2}} \\[/tex]

[tex]v = 0.399c[/tex]

Answer:

b

Explanation:

Answer:

The correct answer is D, diatoms have glass-like cell walls.

Answer:

Explanation:

Problem relates to diffraction of light . Location for 2 nd diffraction minima is

[tex]x=2\times\frac{\lambda D}{d}[/tex]  where λ is wavelength of light , D is distance of screen , d is slit width .

Puting the values

[tex]x=2\times\frac{620D}{d}[/tex]

for unknown wavelength , position of third diffraction is

[tex]x=3\times\frac{\lambda D}{d}[/tex]

from these two equations

[tex]x=2\times\frac{620D}{d}[/tex][tex]=3\times\frac{\lambda D}{d}[/tex]

λ = 413.33 nm .

Answer:

  v = 10 m / s

Explanation:

For this exercise we will use the relationship between the speed of a wave and its frequency and wavelength

         v = λ f

the wavelength is the distance at which the wave repeats, in this case the distance between the two ridges λ = 48 m.

the frequency is the number of oscillations per unit of time, it is also the inverse of the period which is the time in a complete oscillation, in this case they give us the time of half a period, ½ T = 2.4 s

   T = 4.8 s

the frequency is

        f = 1 / T

        f = 1 / 4.8

        f = 0.2083 Hz

let's calculate

        v = 0.2083 48

        v = 10 m / s

Answer:

as in motor generaror are connected to same shaft then both machines are working with same speed

but number of poles are different with same speed means both machines are working with different frequencies

we know

frequency F = N*P/120

speed N = 82120F/P

given

motor speed = generator speed

120F1/P1 = 120F2/P2

F1/P1 = F2/P2

output frequency is 25 which is obtained from generator so F2=25

input frequency is 60 which is given to motor soF1=60

60/P1 = 25/P2

60/25 = P!/P2

P1/P2 = 12/5

multiply and divided by 2 becuase poles are even

P1/P2 = 12*2/5*2

=24/10

P1= 24 poles a

P2 =10 poles we get 25 hz frequency from 60 hz frequency

Answer:

The wire would stick to the magnet????????????????????????

Explanation:

Answer:

Supernovae produce intense flashes of light that can last from several weeks to several months. They are characterized by a rapid increase in light intensity until reaching an absolute magnitude greater than the rest of the galaxy. Subsequently, its brightness decreases more or less smoothly until it disappears completely.

Explanation:

A team of international astronomers discovered that if the supernovae were found at a distance of 50 light years from Earth, they could cause the mass extinction of living things, according to an article published in the Astrophysical Journal.

"Until recently, our colleagues believed that the 'range' of supernovae was about 25 light years. We were of the opinion that they did not take into account a number of factors and that it is actually about 50 light years," Adrian said. Melott, from the University of Kansas at Lawrence (USA).

 The unusually high power of cosmic rays in the atmosphere, according to Melott, results in an increase in the "damage radius" of supernovae. According to the researcher, supernova explosions are capable of destroying life within a radius of 50 light years and not 10 or 25 light years, as previously thought.

Answer:

[tex]\bf{r=\frac{2r_o}{3}}[/tex] is greatest

Explanation:

Given:

[tex]S(r)=ar^2(r_{o}-r)[/tex]

[tex]\frac{ds}{dr}=2ar(r_{o}-r)+ar^2(-1)[/tex]

[tex]\frac{ds}{dr}=2ar_{o}-2ar^2-ar^2[/tex]

[tex]\frac{ds}{dr}=2ar_{o}-3ar^2[/tex]

Substitute [tex]\frac{ds}{dr} = 0[/tex], so

[tex]2ar_{o}-3ar^2=0[/tex]

Then, get the common value from the equation.

[tex]ra(2r_{o}-3r) = 0[/tex]

[tex]\bf{r=0}\\r=\frac{2r_{o}}{3}[/tex]

[tex](\frac{d^2s}{dr^2})_{r=0}=2ar_{o}-6ar[/tex]

[tex](\frac{d^2s}{dr^2})_{r=0}=2ar_{o} >0\;and, \\(\frac{d^2s}{dr^2})_{r}=\frac{2r_o}{3} <0[/tex]

So, the speed of the air is greatest.

[tex]\bf{r=\frac{2r_o}{3}}\;is\;greatest[/tex]

Answer:

Minority group - People who are singled  out for unequal treatment  and who regard  themselves as objects of  collective discrimination.

Ethnicity - A shared identity based on  cultural elements such as  heritage, language, and  religion.

Majority group - A group's subset that  consists of more than half  of the entire group's  members.

Race - A socially constructed  group of people who share  physical characteristics  that are considered  significant by a society  and that are used to  distinguish them from  other groups.

Explanation:

To better understand the above-mentioned definitions we would use some examples:

Elder people can be considered as a minority group in the United States because of their reduced status as a consequence of popular discrimination and prejudice against them. In contrast to them, young men consisting of more than half the population in the age category is an example of the majority group.

Groups of people like Hispanic Americans, Jews, Italian America, Irish are some examples of people belonging to different ethnic backgrounds residing in the U.S.

African Americans who are distinguished based on their skin color is an example of race.

Answer:

The work will be "600 kJ/kg".

Explanation:

(1-a) ⇒ Constant Pressure

(a-2) ⇒ Constant Volume

The given values are:

In state 1,

Pressure, P₁ = 200 kPa

Volume, V₁ = 2m³

In state 2,

Pressure, P₂ = 1000 kPa

Volume, V₁ = 5m³

Now,

In process (1-a), work will be:

⇒ W₁₋ₐ = P₁(Vₐ - V₁)

On putting the values, we get

⇒ W₁₋ₐ = 200(5-2)

⇒         = 200(3)

⇒         = 600 kJ/kg

In process (a-2), work will be:

⇒ Wₐ₋₂ = 0

∴ (The change in the volume will be zero.)

So,

⇒ Total work = (W₁₋ₐ) + (Wₐ₋₂)

⇒                    = 600 + 0

⇒                    = 600 kJ/kg

Answer is Weaker. If it is talking about the objects' gravitational forces.

Answer:

  λ = 0.64 10⁻⁶ m = 640 nm

Explanation:

The two reflected rays experience constructive interference, if we can see them, so we can one condition for interference, but let's see two phenomena that occur

* A ray when it is reflected by a surface of major spare part index has a phase change of 180º, these passes at the air-plastic interface

* A ray when passing a material with a refractive index changes its wavelength

       λ= λ₀ / n

taking into account these facts the condition in constructive interference is

             2 n t = (m + ½) λ

             λ= 2 n t / (m + ½)

if we suppose that we have the first inference m = 0

            λ = 2 1.6 0.5 10⁻⁶ (0 + ½)

            λ = 3.2 10⁻⁶ m

this wavelength is in the infrared

suppose an interference of m = 1

          λ = 1.6 10⁻⁶ / (1 + 1/2)

          λ = 1.06 10-6 m

m = 2

         λ = 1.6 10⁻⁶ / (2 + 1.5)

         λ = 0.64 10⁻⁶ m

this wavelength corresponds to the visible range (640 nm) orange

Answer:

A: 1.962

B: 3.924

Explanation:

g = G *M /R^2

g = 9.807*M/R^2 the gravitational constant of ground level on earth is about 9.807

g = 9.807*5lbs/R^2 the average brick is about 5 pounds.

g = 9.807*5*10^2.   I'm assuming the height is around ten feet to help you out.

with these numbers plugged in you get an acceleration of 0.4905 a final velocity after 4 seconds 1.962. It's height fallen after 4 seconds is 3.924.

( M = whatever the brick weighs it's not specified in the question)

(R = the distance from the ground or how high the scaffold is)

(hopefully you can just plug your numbers in there hope this helps)

Answer:

1 A

Explanation:

P = IV

120 W = I (120 V)

I = 1 A

Answer:30N

Explanation:

Mass=5kg

Acceleration=6m/s^2

Force=mass x acceleration

Force=5 x 6

Force=30N

Answer:

30n

Explanation:

Mass=5kg

Acceleration=6m/s^2

Force=mass x acceleration

Force=5 x 6

Force=30N

Answer:

L= 276.4 mm

Explanation:

Given that

E= 180 GPa

d= 3.7 mm

F= 1890 N

ΔL= 0.45 mm

We know that ,elongation due to load F in a cylindrical bar is given as follows

[tex]\Delta L =\dfrac{FL}{AE}[/tex]

[tex]L=\dfrac{\Delta L\times AE}{F}[/tex]

Now by putting the values in the above equation we get

[tex]L=\dfrac{0.45\times 10^{-3}\times \dfrac{\pi}{4}\times (3.7\times 10^{-3})^2\times 108\times 10^9}{1890}\ m[/tex]

L=0.2764 m

L= 276.4 mm

Therefore the length of the specimen will be 276.4 mm

Answer:

The correct option is a , c

Explanation:

Generally the  fringe spacing is mathematically defined as

        [tex]y = \frac{m \lambda D}{d}[/tex]

Where y is the fringe spacing

           m is the order of the fringe

           [tex]\lambda[/tex] is the wavelength

           D is the distance between the slit and the screen

           d is the distance between the slit

Now in order to increase the fringe spacing can do the following

The following action would increase the fringe spacing because the from the question these parameters are directly proportional to the fringe spacing

Answer:

1/2

Explanation:

Solution:-

- The torque ( T ) induced at the pivotal point of the massless rod-disk assembly is given by:

                           T = M*g*r*sin ( θ )

Where,

              M: The mass of the disk

              r: the radius of the disk

              θ: The precession angle

- The rate of change in angular momentum of the disk ( dL / dt ) is due to the induced torque ( T ) given by:

                          dL / dt = M*g*r*sin ( θ )

Hence,

                          dL = M*g*r*sin ( θ ). dt  ... Eq1

- The change in precession angle ( dθ ) is a orthogonal component of change in angular momentum ( dL ) :

                         dθ = dL / ( L*sin ( θ ) ) ... Eq2

- Combine Eq1 and Eq2:

                         dθ = M*g*r*sin ( θ ). dt / ( L*sin ( θ ) )

                         dθ/dt = M*g*r / L   ... Eq3

Where,

- The angular momentum of the disk is given by the product of moment of inertia ( I ) and angular velocity ( w ):

                      [tex]L = I*w\\\\L = \frac{1}{2}*M*r^2*w[/tex]

- Substitute the relationship of angular momentum of disk ( L ) into Eq3:

                      dθ/dt = M*g*r / 0.5*M*r^2*w                

- Hence, the rate of change of precession ( dθ/dt ) is given by:

                      dθ/dt = 2*g / r*w  

- If we double the mass ( M to 2M ) there is no effect on the rate of change of precession ( dθ/dt ). However, if we double the radius of the disk the rate of precession ( dθ/dt ) is halved due to the inverse relationship between the rate of precession ( dθ/dt ) and radius of the disk.

Answer:The factor of change would be ( 1 / 2 ) of the initial rate of change in precession.

Answer:

t = 2.68 x 10¹⁴ years

Explanation:

First we need to find the amount of energy that Sun produce in one day.

Energy = Power * Time

Energy of Sun in 1 day = (3.839 x 10²⁶ W)(1 day)(24 hr/1 day)(3600 s/ 1 hr)

Energy of Sun in 1 day = 3.32 x 10³¹ J

Now, the time required by the nuclear power generator, in years, will be:

Energy of power generator = Energy Sun in 1 day = 3.32 x 10³¹ J

3.32 x 10³¹ J = Power * Time

3.32 x 10³¹ J = (3.937 x 10⁹ W)(t years)(365 days/1 year)(24 hr/1 day)(3600 s/ 1 hr)

t = 3.32 x 10³¹ /1.24 x 10¹⁷

t = 2.68 x 10¹⁴ years

Answer:

He needs clay gravel and rocks with cracks

Answer:

He starts accelerating until he reaches terminal speed. (Or the maximum velocity attainable by an object)

Explanation: