What is calibration of thermometer?​

Answer:

B. Why the expansion of the universe is accelerating

Explanation:

possibly pretty sure if not right then the answer is A. What dark matter is made of hope this helps please mark brainiest only answer plz

Why the expansion of the universe is accelerating is what scientists know

about the future of the universe.

Scientists have observed that radiation emitted by the galaxies have shifted

towards the red end of the electromagnetic spectrum. This means that there

has been an increase in the wavelength for this to occur.

This tells us that the universe is expanding which was why the wavelength

of the emission spectra experienced a shift or stretch.

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Answer:

1.9981 * 10^24 Kg

Explanation:

Given that

R = 15 * 10^3

ω = 1 rev/s = 2π rad/s

From;

g =GM/R^2  - Rω^2

If g = 0

M = R ^3ω^2/G

M = (15 * 10^3)^3 * (2π)^2/6.67 * 10^-11

M = 1.9981 * 10^24 Kg

Answer:

2.6kgm/s

Explanation:

Momentum is the product of mass of an object and its velocity

Change in momentum = mass × change in velocity

Change in momentum = m∆v

Given

Mass m =2kg

Change in velocity ∆v = 4.5-3.2

∆v = 1.3m/s

Change in momentum = 2×1.3

Change in momentum = 2.6kgm/s

Hence the object change in momentum is 2.6kgm/s

Answer:

all of those are pisitions

Explanation:

Answer:

1.84 m

Explanation:

For the small lead ball to be balanced at the tip of the vertical circle just before it is released, the reaction force , N equal the weight of the lead ball W + the centripetal force, F. This normal reaction ,N also equals the tension T in the string.

So, T = mg + mrω² = ma where m = mass of small lead ball, g = acceleration due to gravity = 9.8 m/s², r = length of rope = 1.10 m and ω = angular speed of lead ball = 3 rev/s = 3 × 2π rad/s = 6π rad/s = 18.85 rad/s and a = acceleration of normal force. So,

a = g + rω²

= 9.8 m/s² + 1.10 m × (18.85 rad/s)²

= 9.8 m/s² + 390.85 m/s²

= 400.65 m/s²

Now, using v² = u² + 2a(h₂ - h₁)  where u = initial velocity of ball = rω = 1.10 m × 18.85 rad/s = 20.74 m/s, v = final velocity of ball at maximum height = 0 m/s (since the ball is stationary at maximum height), a = acceleration of small lead ball = -400.65 m/s² (negative since it is in the downward direction of the tension), h₁ = initial position of lead ball above the ground = 1.3 m and h₂ = final position of lead ball above the ground = unknown.

v² = u² + 2a(h₂ - h₁)

So, v² - u² = 2a(h₂ - h₁)

h₂ - h₁ =  (v² - u²)/2a

h₂ =  h₁ + (v² - u²)/2a

substituting the values of the variables into the equation, we have

h₂ =  1.3 m + ((0 m/s)² - (20.74 m/s)²)/2(-400.65 m/s²)

h₂ =  1.3 m + [-430.15 (m/s)²]/-801.3 m/s²

h₂ =  1.3 m + 0.54 m

h₂ =  1.84 m

Explanation:

Energy is the most important ingredient for life. Organisms use energy in diverse ways. Scientifically, energy is defined as the ability to do work. Without this ability, organisms would not exist.

So, the most important process is one that can furnish the body with energy.

Answer: 4.6

Explanation:

Answer:

4.6

Explanation:

Answer:

1. Fertilization allows an organism to receive a complete set of chromosomes -one set each parent.

Explanation:

Answer:

Force, distance, energy

Explanation:

An impulse is a force acting over some amount of time to cause a change in momentum. On the other hand, work is a a force acting over some amount of distance to cause a change in energy

An impulse is a force acting over some amount of time to cause a change in momentum. On the other hand, work is a a force acting over some amount of distance to cause a change in kinetic energy."

The given problem is based on the concept of impulse and the work done. As per the impulse momentum theorem, when some magnitude of force is applied on an object for a small interval of time, then it will cause some momentum change.

That is,

[tex]F \times t = \Delta P[/tex]

here, F is the applied force.

And as per the concept of work energy theorem, "the work done by the applied force to cause the displacement of an object is equivalent to the change in the kinetic energy of object.

That is,

[tex]W = \Delta KE\\F \times d=\Delta KE[/tex]

here, F is the applied force and d is the distance moved by object.

Thus, we can conclude that the complete paragraph is,

"An impulse is a force acting over some amount of time to cause a change in momentum. On the other hand, work is a a force acting over some amount of distance to cause a change in kinetic energy."

Learn more about the work energy theorem here:

https://brainly.com/question/24509770

Answer:

All measurements of motion will be compared to a frame of reference. Therefore, the most commonly used frame of reference is Earth itself, even though it moves.

Explanation:

Answer:

it change by the pressure of the air and how its pulling the elastic even more

Explanation:

therefore it changes shape and has more differences than before sometimes the colour of it will go lighter if a lot of air and darker if not a lot

Answer:

8.04 × 10¹⁶ photons per second

Explanation:

First, we calculate the energy per photon from E = hc/λ where h = Planck's constant = 6.63 × 10⁻³⁴ Js c = speed of light = 3 × 10⁸ m/s and λ = wavelength of laser = 987 nm = 987 × 10⁻⁹ m = 9.87 × 10⁻⁷ m

So, E = hc/λ = 6.63 × 10⁻³⁴ Js × 3 × 10⁸ m/s/9.87 × 10⁻⁷ m = 19.89/9.87 × 10⁻¹⁹ J = 2.02 × 10⁻¹⁹ J per photon.

Since we have a total of 0.52 J over a period of 32 s, the output power is 0.52 J/32 s = 0.0163 J/s.

Thus the total number of photons per second is thus in output power/energy per photon = 0.0163 J/s ÷ 2.02 × 10⁻¹⁹ J per photon

= 8.04 × 10¹⁶ photons per second

This question is incomplete, the complete question is;

A 13 kg box rests on the flat surface. The coefficient of static friction and coefficient of kinetic friction is μ_s = 0.450 and μ_k = 0.380 respectively.

Let's say you got tired and you are now pushing with a force of 36 N. Find the acceleration of the box.

Answer: the acceleration of the box is 0.9548 m/s²    {backward}

Explanation:

Given that;

mass m = 13 kg

pushing the box with a force of 36 N

the acceleration of the box = ?

ones the box starts moving, kinetic frictional force starts acting.

so

f_k = μ_k × m × g

we substitute

f_k = 0.380 × 13 × 9.8

f_k = 48.412 N

force needed to keep it in motion is 48.412 N

so

Acceleration = Net Force / mass

Acceleration = (48.412 N - 36 N) / 13

Acceleration = 12.412 / 13

Acceleration = 0.9548 m/s²    {backward}

Therefore, the acceleration of the box is 0.9548 m/s²   {backward}

Answer:

[tex]T_B=(\frac{T}{\sqrt{8}})[/tex]

Explanation:

Distance of Planet A from Central star 2R

Time of Resolution T_A=T

Distance of Planet B from orbit star R

Generally the equation for Kepler's law of periods is given by

   [tex]\frac{T_A^2}{T_B^2}=\frac{R_A^3}{R_B^3}[/tex]

   [tex]T_B^2=T_A^2 \frac{R_A^3}{R_B^3}[/tex]

  [tex]T_B^2=T_A^2 (\frac{R_A}{R_B})^3[/tex]

  [tex]T_B^2=T^2 (\frac{R}{2R})^3[/tex]

  [tex]T_B^2=T^2 (\frac{1}{R})^3[/tex]

  [tex]T_B^2=(\frac{T^2}{8})[/tex]

Therefore the following expressions is correct for the number of hours it takes Planet B to complete one revolution around the star

  [tex]T_B=(\frac{T}{\sqrt{8}})[/tex]

The number of hours that it takes for planet B to complete one revolution around the star is : ( A ) (  [tex]\frac{T}{\sqrt{8} }[/tex] )

Given data :

Distance of Planet A from massive star = 2R

Time taken by Planet A to orbit the massive star = Tₐ

Distance of Planet B from massive star = R

Time taken by Planet B to orbit the massive star = T[tex]_{b}[/tex]

To determine the proper expression exhibiting the correct number of hours it will take for Planet B to complete a revolution

we will apply Kepler's law of periods

[tex]\frac{T^{2} _{a} }{T_{b} ^{2} } = \frac{R_{a} ^{3} }{R_{b} ^{3} }[/tex]

∴ [tex]T_{b} ^{2} = T_{a} ^{2} ( \frac{R_{a} }{R_{b} } )^{3}[/tex]

[tex]T_{b} ^{2} = T^2 ( 1/R)^3[/tex]

Hence T[tex]_{b}[/tex] = (  [tex]\frac{T}{\sqrt{8} }[/tex] )

There we can conclude that The number of hours that it takes for planet B to complete one revolution around the star is : ( A )  (  [tex]\frac{T}{\sqrt{8} }[/tex] )

Learn more about kepler law of periods : https://brainly.com/question/929044

Answer:

2.7MJ

Explanation:

Power is expressed according to the formula

Power = work done/Time

The energy required is also known as the work done

Given

Power = 750Watts

Time = 1hr = 3600secs

Substitute the given values into the formula

750 = work done/3600

Work done = 750×3600

Work done = 2,700,000Joules

Convert to megajoules

Since

1MJ = 10^6Joules

x = 2.7×10^6Joules

Cross multiply

10^6x = 2.7×10^6

x = 2.7×10^6/10^6

x = 2.7

Hence the amount of energy absorber by the food in MJ is 2.7MJ

Answer:

Physical change is different to chemical change by that physical changes can be reversed, meaning it can be turned back to its original form, but chemical changes CANNOT! Chemical change is something that creates a NEW substances that cannot be reversed. It creates new forms.

Explanation:

Example of chemical change: Change in texture- fried egg. It cannot be turned back to its original form after it is fried.

I truly hope this is helpful!!

If so, please, please mark brainliest, i haven’t got any!

Thanks! Have  wonderful day! :)

Answer:

70000N/m

Explanation:

Work is Force multiplied by Displacement.

Multiply 700 by 100 and you get 70000N/m

*Note: N is newtons and m is meters.

Answer: 7000N/m

Explanation: 700 x 100 = 7000

Complete Question:

Which one of the following is a

true statement?

Group of answer choices.

A) The second law of thermodynamics is a consequence of the first law of thermodynamics.

B) It is possible for heat to flow spontaneously from a hot body to a cold one or from a cold one

to a hot one, depending on whether or not the process is reversible or irreversible.

C) It is not possible to convert work entirely into heat.

D) It is impossible to transfer heat from a cooler to a hotter body.

E) All of these statements are false.

Answer:

E) All of these statements are false.

Explanation:

All of the following statements are false;

I. The second law of thermodynamics is a consequence of the first law of thermodynamics. The second law of thermodynamics is about a physical quantity known as entropy while the first law of thermodynamics states that energy cannot be created or destroyed but can only be transformed from one form to another.

II. It is possible for heat to flow spontaneously from a hot body to a cold one or from a cold one

to a hot one, depending on whether or not the process is reversible or irreversible. According to the second law of thermodynamics this is false due to the entropy.

III. It is not possible to convert work entirely into heat. It is possible to completely convert work into heat because it involves transferring energy.

IV. It is impossible to transfer heat from a cooler to a hotter body.

Answer:

13.75m/s; 42.2m; 8s

Explanation:

(a) the car's velocity after 2.50 s is 13.75 m/s

(b) The distance traveled by the car is 42.18 m

(c)  the time taken for the car to come to complete stop is 8 s.

The given parameters;

mass of the car, m = 2500 kg

initial velocity of the car, u = 20 m/s

breaking applied on the car, f = 6250 N

The acceleration of the car is calculated as follows;

[tex]F = ma \\\\a = \frac{F}{m} = \frac{6250}{2500} = 2.5 \ m/s^2[/tex]

(a) Using impulse-momentum theorem, the car's velocity after 2.5 s is calculated as follows;

[tex]F = \frac{m(u-v)}{t} \\\\m(u-v) = Ft\\\\u-v = \frac{Ft}{m} \\\\v = u - \frac{Ft}{m} \\\\v = 20 - \frac{6250 \times 2.5}{2500} \\\\v = 13.75 \ m/s[/tex]

(b) The distance traveled by the car during the 2.5 s;

[tex]v^2 = u^2 - 2as\\\\2as = u^2 - v^2\\\\s = \frac{u^2 - v^2}{2a} \\\\s = \frac{20^2 - 13.75^2}{2\times 2.5} \\\\s = 42.18 \ m[/tex]

(c) The time taken for the car to come to a complete stop;

when the car stop's the final velocity, v = 0

v = u - at

0 = 20 - 2.5t

2.5t = 20

[tex]t = \frac{20}{2.5} \\\\t = 8 \ s[/tex]

Thus, the time taken for the car to come to complete stop is 8 s.

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Answer:

1.23×10⁶ J

Explanation:

From the question given above, the following data were obtained:

Velocity (v) = 65 m/s

Mass (m) = 580 Kg

Kinetic energy (KE) =?

The kinetic energy can be obtained by using the following formula :

KE = ½mv²

Where:

KE => is the kinetic energy.

m => is the mass

v => is the velocity

With the above formula, we can obtain the kinetic energy as follow:

Velocity (v) = 65 m/s

Mass (m) = 580 Kg

Kinetic energy (KE) =?

KE = ½mv²

KE = ½ × 580 × 65²

KE= 290 × 4225

KE = 1.23×10⁶ J

Thus, the kinetic energy is 1.23×10⁶ J

It is a false statement that a person should be able to find all the answers to their science questions in the text because there are billions of scientific questions and it is almost impossible for any kind of textbook to contain all the answers.

Science is the methodical, empirically-based pursuit and application of knowledge and understanding of the natural and social worlds.

A method of learning about the world is science. Science allows people to participate in the creation of new knowledge as well as use that knowledge to further their goals.

The idea that someone should be able to find all the answers to their scientific inquiries in the text is untrue since there are countless unanswered scientific questions, making it nearly impossible for any textbook to provide them all.

Thus, the statement is false.

Learn more about the science here, refer to the link ;

https://brainly.com/question/18186842

#SPJ2

Answer:

1 hat

Explanation:

Answer:

The mass of the object is 5.045 lbm.

Explanation:

Given;

kinetic energy of the object, K.E = 1558.71 ft.lbf

velocity of the object, V = 141 ft/s

The kinetic energy of the object is calculated as;

[tex]K.E = \frac{1}{2} mV^2\\\\mV^2 = 2K.E\\\\m = \frac{2K.E}{V^2} \\\\1 \ lbf = 32.174 \ lbm.ft/s^2\\\\m = \frac{2 \ \times \ 1558.71 \ ft.lbf \ \times \ 32.174 \ lbm.ft/s^2 }{(141 \ ft/s)2 \ \ \times \ \ \ \ 1 \ lbf\ }[/tex]

[tex]m = \frac{(2 \ \times \ 1558.71 \ \times \ 32.174) \ lbm.ft^2/s^2 }{(141 )^2\ ft^2/s^2 }\\\\m = \frac{(2 \ \times \ 1558.71 \ \times \ 32.174) \ lbm }{(141 )^2 }\\\\m = 5.045 \ lbm[/tex]

Therefore, the mass of the object is 5.045 lbm.

Answer:

Pretty sure it’s A

Explanation:

Would ike brainliest

Answer:

2880 (m)

Explanation:

1. the formula of distance is: L=v*t, where L - the required distance; v - average velocity; t - elapsed time.

2. if t=1.2 hours, it means 72 minutes, then

3. L=40*72=2880 m.

all except the rubber boots.

The answers should be The power lines themselves and The metal tools the worker uses (the 1st and 4th choices).

(For anyone curious, the image I attached to this answer is the image given for this problem.)

Answer:2.81 N

Explanation:

Given

[tex]q_1=3\times 10^{-6}\ C\\q_2=-1.5\times 10^{-6}\ C[/tex]

distance between them r=0.12 m

Electrostatic force is [tex]F=\frac{kq_1q_2}{r^2}[/tex]

Putting values

[tex]F=\dfrac{9\times 10^9\times (3\times 10^{-6})\times (-1.5\times 10^{-6})}{0.12^2}\\F=2.81\ N[/tex]