the moon revolves around the earth in a nearly circular orbit kept by gravitational force exerted by the earth work done will be

Answer:

1. a) Astronomers use the parallax method to measure the distance to nearby stars, but

we can’t use it to measure the distance to stars in other galaxies. Why not? Why isn’t the

parallax method useful for measuring the distances to stars in other galaxies?

They are so distant that the parallax is too small to be measured since parallax varies

inversely with distance.

b) Instead of the parallax method, we use the standard candle method to measure the

distance to stars in other galaxies. In particular, we use the standard candle method to

measure the distances to Cepheid variable stars in other galaxies. What is special about

Cepheid variable stars that makes them useful for this purpose?

We can figure out their luminosities from their periods of variation. Then if we measure

their fluxes we can calculate their distances.

2. a) From what were the protons and electrons in your body made, and roughly when

were they made?

They were made from energy (or gamma rays) very soon after the big bang (in the first

second). 400,000 years later they got together to make hydrogen atoms.

b) From what were the carbon atoms in your body made, and where were they made?

They were not made in the big bang. They were made much later inside of stars or in

supernovae. They were made by fusion from lighter atoms.

3. Make two sketches of the Milky Way Galaxy, one an edge-on view and one a face-on

view, labeling the various parts of the galaxy.

You should have labeled the

Explanation:

(i) The horizontal component of the tension in the right wire points right, and the horizontal component of the tension in the left wire points left.  Since these components are equal and opposite, the resultant horizontal force is 0.

∑Fₓ = 15 N cos 20° − 15 N cos 20°

∑Fₓ = 0 N

(ii) ∑Fᵧ = 15 N sin 20° + 15 N sin 20°

∑Fᵧ = 10.26 N

i) The resultant horizontal component of the tension forces is 0N

ii) The resultant vertical component of the tension forces is 10.26N

iii) The sum of force along the horizontal is zero because the force has the same magnitude and moving in the opposite direction.

i) From the given figure, the horizontal component of the force is given as;

[tex]F_x = + 15 cos 20^0 + (-15cos20^0)\\F_x = + 15 cos 20^0 -15cos20^0\\F_x =0[/tex]

The sum of force along the horizontal is zero because the force has the same magnitude and moving in the opposite direction.

ii) The vertical component of the force is expressed as

[tex]F_y = + 15 sin 20^0 + 15sin20^0)\\F_y = 2(15sin20^0)\\F_y=2(5.13)\\F_y=10.26N[/tex]

Hence the resultant vertical component of the tension forces is 10.26N

Learn more here: https://brainly.com/question/24524696

Answer:

well done buddy

Explanation:

Answer:

a)  T = 1.26 s , b)  v_max = 0.14 m / s ,  a_max = 0.7 m / s²

c) x = 0.028 cos (5 t) ,    v = - 0.14 sin 5t,   a = - 0.7 cos 5t

Explanation:

This is a simple harmonic motion exercise that is described by the equation

    x = A cos (wt +Ф)

with

          w = √ (k / m)

let's apply this expression to our case

a) Angular velocity is related to frequency

          w = 2π f

frequency and period are related

          f = 1 / T

we substitute

         2π / T = √ (k / m)

         T = 2π √(m / k)

let's calculate

         T = 2π √(1/25)

          T = 1.26 s

In the expression for the period, the amplitude does not appear, therefore there is no dependence, as long as Hooke's law is fulfilled, which is correct for small amplitudes.

b) in the initial equation we have the position as a function of time, let's use the definition of speed and acceleration

           v = dx / dt

           v = - A w sin (wt + Ф)

the speed is maximum when the sine is -1

            v_max = A w

            w = √ (k / m)

            w = √ 25/1

            w = 5 rad / s

the amplitude of the movement is equal to the maximum compression of the spring

            A = 2.8 cm = 0.028 m

we substitute

            v_max = 0.028 5

            v_max = 0.14 m / s

acceleration

             a = dv / dt

             a = - A w² cos (wt + Ф)

the acceleration is maximum when the cosine is -1

             a_max = A w²

let's calculate

             a_max = 0.028 5²

             a_max = 0.7 m / s²

c) let's start by finding the phase constant

              v = -A w cos (wt + Ф)

at t = 0 they indicate that the system has v = 0

              0 = -A w sin (0 + Ф)

              Ф = sin⁻¹ 0

              Ф = 0

we write the equation

            x = 0.028 cos (5 t)

           v = - A w sin (wt + Ф)

           v = - 0.028 5 sin (5t + 0)

           v = - 0.14 sin 5t

acceleration

           a = - A w² cos (wt + Ф)

           a = - 0.028 5 2 cos (5 t + 0)

           a = - 0.7 cos 5t

Answer:

I should be active for 15 hours to meet the physical activity requirement.

Explanation:

Since time dilates in moving objects, we use the formula t = t₀/√(1 - β²) where t = time in space vehicle, t₀ = time on earth = 9 hours and β = v/c where v = speed of space vehicle = 0.8c.

So, t = t₀/√(1 - β²)

t = 9/√(1 - (v/c)²)

= 9/√(1 - (0.8c/c)²)

= 9/√(1 - (0.8)²)

= 9/√(1 - (0.64)

= 9/√0.36

= 9/0.6

= 15 hr

So, according to a timer on the space vehicle, I should be active for 15 hours to meet the physical activity requirement.

Answer:

A. It is always a positive force

Explanation:

Hooke's law describes the relation between an applied force and extension ability of an elastic material. The law states that provided the elastic limit, e, of a material is not exceeded, the force, F, applied is proportional to the extension, x, provided temperature is constant.

i.e F = - kx

where k is the constant of proportionality, and the minus sign implies that the force is a restoring force.

The applied force can either be compressing or stretching force.

Answer:

Physics is the branch of science concerned with the nature and properties of matter and energy. The subject matter of physics, distinguished from that of chemistry and biology, includes mechanics, heat, light and other radiation, sound, electricity, magnetism, and the structure of atoms. And a more detailed working definition of physics may be: The science of nature, or that which pertains to natural objects, which deals with the laws and properties of matter and the forces which act upon them. Quite often, physics concentrates upon the forces having an impact upon matter, that is, gravitation, heat, light, magnetism, electricity, and others.

Physics helps us to understand how the world around us works, from can openers, light bulbs and cell phones to muscles, lungs and brains; from paints, piccolos and pirouettes to cameras, cars and cathedrals; from earthquakes, tsunamis and hurricanes to quarks, DNA and black holes. Physics helps us to organize the universe. It deals with fundamentals, and helps us to see the connections between seemly disparate phenomena.

Physics provides quantitative and analytic skills needed for analyzing data and solving problems in the sciences, engineering and medicine, as well as in economics, finance, management, law and public policy. Physics is the basis for most modern technology, and for the tools and instruments used in scientific, engineering and medical research and development. Manufacturing is dominated by physics-based technology.

To understand the fundamental principles of the universe, physics utilizes many workings from the other natural sciences. Because of this overlap, phenomena studied in physics (conservation of energy for example) are common to all material systems. The specific ways in which they apply to energy (hence, physics) are often referred to as the "laws of physics." Because each of the other natural sciences biology, chemistry, geology, material science, medicine, engineering, and others, work with systems which adhere to the laws of physics, physics is often referred to as the "fundamental science."

Answer:

Physics can be important in understanding the world and how it works. The  main goal of physics is to understand how the universe behaves.

Explanation:

Answer:

1.25 m/s

Explanation:

divide 120 by 120 to get one second and then divide 1t0 by 120 to get the number

Answer:

h = 35857 km

Explanation:

A geosynchronous orbit can be defined as circular orbit which lies on the Earth's equatorial plane and follows the direction of the Earth's rotation in a period that's equal to the Earth's rotational period and thereby appearing motionless, at a fixed position in the sky relative to the ground observers.

We are given;

Radius of earth(R) = 6.37 x 10^(6) m

Mass of earth (Me) = 5.97 x 10^(24) kg

Gravitational constant = 6.67 × 10^(-11) m³/kg.s²

The earth has a rotational period of 24 hours per day. This gives in seconds

T = 24 × 60 × 60

T = 86400 s

Let's make the height of the orbit from Earth's surface to be h

Also, let ω be the uniform angular velocity in rad/s with which the satellite rotates in the geosynchronous orbit

Now, equating the centripetal force with the gravitational force gives us;

mω²(R + h) = G•Me•m/(R + h)²

m will cancel out. Also ω can be written as 2π/T

Thus,we now have;

(R + h) = ∛(G•Me•T²/(4π²))

Plugging in the relevant values, we have;

(R + h) = ∛(6.67 × 10^(-11) × 5.97 x 10^(24) × 86400²/(4π²))

(R + h) = 42227 Km

Since R = 6.37 x 10^(6)m = 6370 km

Thus;. h = 42227 - 6370 = 35857 km

Answer:

.21

Explanation:

i see everyone got it wrong so ill give you the answer, good luck :)

Answer:

1 Watt

Explanation:

Power (P) = w / Δt

w = work done

Δt = change in time

Power (P) = 60kg / 60 seconds

Power (P) = 1 Watt

The amount of force required to move the object is 64,800N

The first step is to write out the parameters given in the question;

Mass= 1200 kg

Velocity= 54 km/hr

The amount of force required to move the object can be calculated as follows;

Force= mass × velocity

= 1200×54

= 64,800N

Hence the amount of force that is required to move the object is 64,800N

Please click on the link below to learn more

https://brainly.com/question/24256124?referrer=searchResults

Answer:

kinetic energy will be equal to 0

Explanation:

this is because at final position velocity of body will become zero.

kinetic energy eill be 8 times

Answer:

In what way is iron unique among the elements?

It has the lowest mass per nuclear particle.

Match words at the left to the correct blanks in the sentences on the right. Not all words will be used.

-The energy that drives the expansion of a star into a subgiant or red giant comes from HYDROGEN SHELL FUSION

-Stars with mass greater than about 8 solar masses are considered HIGH-MASS STARS

-The final stage of core fusion in a low-mass star is HELIUM FUSION

-Stars that are fusing hydrogen in their cores are MAIN-SEQUENCE STARS

-When it dies, a high-mass star explodes as a SUPERNOVA

-A star that is expanding (into a subgiant and then a giant) has a(n) INERT HELIUM CORE

-When it dies, a low-mass star expels a PLANETARY NEBULA

-Stars with masses less than about two solar masses are considered LOW-MASS STARS

Answer:

Chemical Energy

Explanation:

Answer:

Because rice mill is more advanced than dhiki.

It is the developed form of the dhiki.

Answer:

12.3 m/s

Explanation:

The Doppler equation describes how sound frequency depends on relative velocities:

fr = fs (c + vr)/(c + vs),

where fr is the frequency heard by the receiver,

fs is the frequency emitted at the source,

c is the speed of sound,

vr is the velocity of the receiver,

and vs is the velocity of the source.

Note: vr is positive if the receiver is moving towards the source, negative if away.

Conversely, vs is positive if the receiver is moving away from the source, and negative if towards.

Given:

fs = 894 Hz

fr = 926 Hz

c = 343 m/s

vs = 0 m/s

Find: vr

926 = 894 (343 + vr) / (343 + 0)

vr = 12.3

The speed of the car is 12.3 m/s.

Answer:

the process of comparing unknown quantities with known standards quantities are known as measurement

The answer to the digits rounded to one significant figure is 100.

Significant figures are the most important figures in a number of digits.

The closer a digit is to the beginning of a number, the more important  or significant  it is.

But, the rule for rounding up a set of numbers to the first significant or to one significant figure is that:

From the numbers 98.907, 9 is the most significant digit followed by 8.

8 is greater than 5 so we should round up by adding one to 9 making the number 100.

learn more here:

https://brainly.com/question/11566364

Answer: gravitational pull? gravity

Explanation:

Answer: i think c

Explanation:QA: “What is ordinary glass made of ?”

Glass is mostly silica, or silicon dioxide, present as quartz in many types of sand. Pure silica forms a highly transparent glass, but has a very high melting or softening temperature, around 1700°C. Even at such high temperatures it is highly viscous and difficult to work. Its use is largely confined to applications requiring high transparency to ultra-violet and infra-red radiation, stability at elevated temperatures or low thermal expansion coefficient.

“Ordinary glass” windows and drinking vessels are typically made from soda-lime glass, containing silica with around 25% sodium, calcium and other oxides, which together reduce the softening temperature to roughly 500–600°C

Explanation:

Wave front, imaginary surface representing corresponding points of a wave that vibrate in unison. ... Wave fronts for longitudinal and transverse waves may be surfaces of any configuration depending on the source, the medium, and the obstructions encountered.

Answer:

20

Explanation:

Atomic number is same as the number of protons of an atom and atomic mass is equal to the sum of number of protons and number of neutrons of an atom.

Atomic number = 19

So, number of protons (p) = 19

Atomic mass = 39

So, sum of number of neutrons and number of protons (n + p) = 39

Number of neutons (n)

= (n + p) - p

= 39 - 19

= 20

Potassium’s atomic number is 19, and its atomic mass is approximately 39, then Potassium would have 20 neutrons present inside its nucleus, therefore the correct answer is option C.

The total number of protons present in an atom is known as the atomic number of that atom. The atomic number has no correlation either with the number of neutrons or the number of electrons present inside an atom.

While the atomic mass of an atom is the sum of the total number of protons and the number of neutrons present inside of any atom.

atomic number= total number of protons

atomic mass = total number of protons + total number of the neutrons

As given in the problem Potassium’s atomic number is 19, this means Potassium has 19 protons

Potassium has an atomic mass of about 39

39 = total number of protons + total number of the neutrons

39 = 19 +  total number of the neutrons

total number of the neutrons = 39-19

                                                 =20

Since potassium has an atomic mass of about 39 and an atomic number of 19, it would have 20 neutrons in its nucleus. Option C is the right response.

Learn more about the atomic number from here

brainly.com/question/14190064

#SPJ5

Answer:

  96 m

Explanation:

The average velocity over those 4 seconds is the velocity after 2 seconds:

  30 m/s -(2 s)(3.0 m/s^2) = 24 m/s

The displacement is the product of this average velocity and the duration of the acceleration:

  d = (24 m/s)(4 s) = 96 m

The boat covered 96 m while being accelerated.

tape measure?

Hope that helped!!! k

instrument is used to measure is Tape measure

Answer with Explanation:

Let me answer this in a simple way, since the density of stone is greater than that of water, the stone sinks as the weight of the stone is greater than the weight of water displaced by it. But the ship is designed in such a way that the relative density of the ship always becomes less than that of water. Therefore, the weight of the water displaced becomes equal to the total weight of the ship and thus it floats.

There are many other ways to explain this but this should give you the general idea.

Answer:

C. The number of shells increases from top to bottom

Explanation:

There are some trends about the periodic table, one of them is that in the vertical columns of periodic table, the number of shells increases from top to bottom.

From top to bottom in a periodic table, the number of electrons increases, thus more number of shells are needed to fill these electrons and the number of shells increases or we can say the atomic radius increases from top to bottom.

Hence, the correct option is "C".

THIS IS YOUR ANSWER :

Archimedes’ principle, physical law of buoyancy, discovered by the ancient Greek mathematician and inventor Archimedes, stating that any body completely or partially submerged in a fluid (gas or liquid) at rest is acted upon by an upward, or buoyant, force, the magnitude of which is equal to the weight of the fluid displaced by the body.

☺✍️HOPE IT HELPS YOU ✍️☺