Guys, can you please answer these three questions. I'm having trouble doing them.
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Answer:

Archaeology

Explanation:

Radioisotopes are radioactive atoms of an element in which their atoms contain excess energy making them unstable. When broken down they become more stable releasing radiations.

Carbon 14 is a radioactive isotope that is used in archaeology to study and estimate the lifespan and age of organic materials such as wood, leather. Carbon 14 can be used to estimate the ages of materials up to 50000 to 60000 years.

Answer:

archaeology

Explanation:

Answer:

Reproducible by other scientists

Explanation:

I just took the test

Answer:

Solution ( for fourth attachment ) : 38°C

Tip : Remember the units °C when submitting answer

Explanation:

As you mentioned, we only need the solution for the fourth attachment.

The idea here is that the heat lost by the metal will be equal to the heat gained by the water. We know that the specific heat gained or lost will always be represented by the following formula,

q = m [tex]*[/tex] c

Therefore if we substitute the know values and equate the two equations knowing that " q " is common among them --- ( 1 )

0.33 [tex]*[/tex] 448

Remember that the change in temperature of iron (ΔT) would be represented by final temperature - initial temperature, or final temperature - 693. Similarly the change in temperature of water will be final temperature - 39. Now we can pose the final temperature as a, and solve for a through substitution --- ( 2 )

0.33 [tex]*[/tex] 448

From here on take a look at the attachment. It represents how to receive get a through simple algebra. Here a, the final temperature, is about 38°C. In exact terms it will be [tex]38.03617\dots[/tex]°C.

Answer:

My answer is radiant energy to chemical energy because it uses the sun which is a form of solar energy and then converts the food to chemical energy for the plant itself

Answer: Radiant energy to chemical energy

Explanation: Right on edge2021

Answer:

The distance traveled by the ball is 8.5 m

Explanation:

Initial height of the ball, h₁ = 1.5 m above the ground

final height of the ball, h₂ = 5m

Upward distance = distance traveled by the ball from a height of 1.5m to 5m = 5m - 1.5m = 3.5 m

Downward distance = distance traveled by the ball from 5m height to the ground =5m - 0 = 5m

Total distance traveled = upward distance + downward distance

Total distance traveled = 3.5 m + 5m = 8.5 m

Therefore, the distance traveled by the ball is 8.5 m

Explanation:

The asked in the Question is missing, although i am assuming the number

as [tex]\frac{6}{23}[/tex] ÷[tex]\frac{\sqrt{2} }{2}[/tex].

The given expression contains an irrational number. So, the quotient will also be an irrational number.

Solving

[tex]\frac{6}{23}\times\frac{\sqrt{2} }{2} \\=\frac{3\sqrt{2} }{23}[/tex]

Which is an irrational number.

Answer:

It will fall at the same speed in both locations

Explanation:

When an object is falling, it is accelerated to the same degree irrespective of the height from which it is falling.

All objects on the earth's surface experience an acceleration due to gravity. This acceleration due to gravity is the same for all objects irrespective of their height or mass.

Hence for a stone dropped from the same height as Terai and the top of a mountain, the acceleration due to gravity is the same in both cases hence they will fall at the same speed.

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:

The answer is below

Explanation:

The efficiency of a machine is the ratio of its output to its input. The efficiency shows how effective the machine by the way it converts the input energy into work. The higher the efficiency of the machine the more effective it is. The efficiency is usually less than 1.

Given that the machine uses diesel oil (input) that can produce 3.0 x 10⁹ J of energy while the work performed by the machine (output) is 2.7 x 10⁸ J. The efficiency is given as:

Efficiency = output / input = 2.7 x 10⁸ J / 3.0 x 10⁹ J = 0.09 = 9%

This means that the machine is not effective because of its low efficiency

Answer:

Explanation:

In all works of life science can be applied, in-fact science has already been applied already, even in the humanities, social sciences and art related studies sciences is being applied,

    Furthermore, the application of science and technology knows no boundaries, and as science is advancing day by day, expanding to new frontiers and breaking new limits so is it application to all works of life and relevance everyday.

Answer:

A: 15 m/s

B: 900 Meters

Explanation:

A. Average speed is equal to final velocity plus initial velocity divided by two

Va= (20+10)/2 = 15 m/s

B.

distance = speed × time

D= 15 m/s * 60s = 900 Meters

Answer:

Answer is in the attachment.

Explanation:

Hope this helps.

Please mark me as Brainliest.

Answer:

Pressure

Explanation:

One of the theories propounded by the Kinetic molecular theory, and which also provides an explanation of the several gas laws, is the statement that the gas molecules in a container, travel in straight lines and are in constant collision with themselves and the walls of the container, thus exerting force. This force is the pressure which is defined as the force per unit area.

There is no loss of energy in the collisions involving the gas molecules and that is why their movement can be described as elastic. The descriptions of the behavior of gas molecules in the Kinetic Molecular Theory, give rise to Charles law, Boyle's Law, Avogadro's Laws, Dalton's Law, and Amonton's Law.

Answer:

The pressure

Explanation:

Molecules of gases are constantly in motion, colliding with the walls of their container. This constant collision impacts force on the walls of the container, which depends on the speed with which the molecules are moving. The speed with which these molecules travel depends on the average kinetic energy of the molecules, which is proportional to the temperature.

This force when exerted per unit area is the pressure the gases exert on the walls of the container.

Answer:

Lens of the human Eye is a important and one of that most complex sense organ.

Explanation:

Lens of the human eye it helps that in visualizing light and color perception and objects , glance on the human eye structure and function.

Sense organs are much pretty similar to the camera they  help us see the objects clear.

A human eye is the 2.3 cm in diameter and all filled some fluid, and there are following parts in eye:-  cornea,  Retina , Lens ,Pupil , optic nerves.

cornea :- the cornea is the first transparent part of is called cornea, enters the light through the cornea.

Retina :-it is light sensitive layer that consists of nerve cells,then transmitted to the brain through nerves.

Lens:- behind the pupil there is a transparent structure called lens,it shape focus light on the retina.

Pupil:-it control the value of light that enters the human eye.

Optic nerves is are the two types :- (1) cones (2) Rods .

Answer:

It causes Light Rays to converge on the retina

Explanation:

I took the K12 Test

Answer:

14.07 units of joules is removed for each joules of electricity used

Explanation:

The heated room temperature [tex]T_{c}[/tex] = 61 °F

The outside temperature [tex]T_{h}[/tex] = 98 °F

For conversion from fahrenheit to kelvin we use the equation

(32°F − 32) × 5/9 + 273.15

[tex]T_{c}[/tex] = 289.26

[tex]T_{h}[/tex] = 309.82

For air conditioning,

COP = [tex]\frac{T_{c} }{T_{h} -T_{c} }[/tex]

COP = [tex]\frac{289.26 }{309.82 -289.26 }[/tex]  = 14.07

This means that 14.07 units of joules is removed for each joules of electricity used

Answer:

Hey there!

Elements only contain one type of atom, and a compound contains atoms of different elements chemically combined together. For example, gold is an element, because it only is made of gold atoms, where water or H2O is a compound.

Let me know if this helps :)

Answer:

A compound contains atoms of different elements chemically combined together in a fixed ratio. An element is a pure chemical substance made of same type of atom. Elements contain only one type of atom.

Example:

Explanation:

Answer:

Gravitational fields are determined only by the mass ( or mass-energy) of a body. ... magnetic fields are produced by charged particles in motion, and depend on the charge and velocity of these particles, but not on their mass. Magnetic fields are 'polar' fields with a North and South polarity.

Explanation:

Answer:

Explanation:

Given that:

For a first order instrument with a sensitivity of .4 mV/K

constant c  = 25 ms = 25 × 10⁻³ s

The initial temperature [tex]T_1[/tex] = 273 K

The final temperature [tex]T_2[/tex] = 473 K

The initial volume = 0.4 mV/K × 273 K = 109.2 V

The final volume =  0.4 mV/K × 473 K =  189.2 V

the instrument’s response as a function of time for a sudden temperature increase can be computed as follows:

Let consider y to be the function of time i.e y(t).

So;

y(t) = 109.2  + (189.2 - 109.2)( 1 - [tex]\mathbf{e^{-t/c}}[/tex])mV

y(t) = (109.2 +  80 ( 1 - [tex]\mathbf{e^{t/25\times 10^{-3}}}[/tex])) mV

Plot the response y(t) as a function of time.

The plot of y(t) as a function of time can be seen in the diagram  attached below.

What are the units for y(t)?

The unit for y(t) is mV.

Find the 90% rise time for y(t90) and the error fraction,

The 90% rise time for y(t90) is as follows:

Initially 90% of 189.2 mV = 0.9 ×  189.2 mV

=  170.28 mV

170.28 mV = (109.2 +  80 ( 1 - [tex]\mathbf{e^{t/25\times 10^{-3}}}[/tex])) mV

170.28 mV - 109.2 mV = 80 ( 1 - [tex]\mathbf{e^{t/25\times 10^{-3}}}[/tex])) mV

61.08 mV =  80 ( 1 - [tex]\mathbf{e^{t/25\times 10^{-3}}}[/tex])) mV

0.7635  mV = ( 1 - [tex]\mathbf{e^{t/25\times 10^{-3}}}[/tex])) mV

t = 1.44 × 25  × 10⁻³ s

t = 0.036 s

t = 36 ms

The error fraction = [tex]\dfrac{189.2-170.28 }{189.2}[/tex]

The error fraction = 0.1

The error fraction = 10%

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:

Explanation:

On rubbing a glass rod with silk, the electrons from the glass rod get transferred to the silk. The silk now has an excess of electrons and so is negatively-charged. On the other hand, the glass rod is deficient in electrons and hence is positively-charged.

In the above case, the silk undergoes negative electrification.

Now, when the positively charged glass rod is touched on the disc of a negatively charged gold leaf electroscope, the electrons shifts towards rod, hence amount of charge on gold leaves decreases and the divergence between the gold leaves decreases as unlike charges attract each other.

Hence, the divergence decreases when a glass rod rubbed with silk is brought near the disc of negatively charged electroscope.

hope it helps pls mark me as brainliest

Answer:

  #_total = 4.38 10⁹ liter

Explanation:

For this exercise we can use a direct proportion rule (rule of three). If 4 people use 1200 liters how much water 1 person consumes

            #_water = 1 person (1200 liter / 4 person)

            #water = 300 liters

Now we look for the consumption of this person in a year, if 1 person consumes 300 liters 1 day, how many liters they consume in a year (365 days)

           #_water_person_total = 365 days (300 liters / 1 day)

           #_water_person_total = 109500 liters

This is the water consumption of 1 person in a year, the total of 40000 people how much they consume

           #_total = 40000 person (109500 liter / 1 person)

           #_total = 4.38 10⁹ liter

Answer:  392N

Explanation: W=mg

                 W= 40x9.8

                     = 392N

Answer:

[tex]\large \boxed{\sf 392.4 \ N}[/tex]

Explanation:

[tex]\sf Weight \ (N) =mass \ (kg) \times acceleration \ of \ gravity \ (m/s^2)[/tex]

[tex]W=mg[/tex]

[tex]W=40 \times 9.81[/tex]

[tex]W= 392.4[/tex]

Each of the three choices is tasteless, exhibitionist, juvenile, and dangerous.  John should do none of them.

Encountering a news crew, there's no reason for John to call attention to himself in a childish way, or interfere with their work in any way.

What he should do is:

==> Slow down

==> Pass the scene cautiously

==> Resume his normal, legal speed quietly, in case the crew happens to be recording audio at the moment.

Mysteriously, this course of action is nowhere to be found among the choices listed.

Answer:

all three options :)

Explanation:

cuz merica

Answer:

Explanation:

The weight of a body is defined as the force with which it is attracted towards the centre of a planet. A spring balance measures it. It's unit is Newton ( N ) in the SI system and dyne in the CGS system.

Hope I helped!

Best regards!

Weight is force.

The CGS unit of force is the dyne.

The SI unit of force is the Newton.

Answer:

a=845.07 m/s2

Explanation:

m=0.142kg

F=120N

a=?

F=m*a /:m

a=F/m

a=120N/0.142kg

a=845,07m/s2

Answer:

a = 845.07 m/s²

Explanation:

As we know ,

as per newton's 2nd law:-

F = ma

therefore

a = F/m

given:

a = ?

F = 120N

m = 0.142 kg

procedure:-

a = 120/0.142

therefore :

a = 845.07 m/s²

Answer: 37.5 km

Explanation:

The question is that

If you ran 15 km/hr for 2.5 hours, how much distance would you cover ?

Where

Speed = 15 km/ hr

Time = 2.5 hours

Using the formula for speed.

Speed = distance/time

Substitute speed and time into the formula

15 = distance/ 2.5

Make distance the subject of formula by cross multiplying.

Distance = 15 × 2.5

Distance = 37.5 km.

Answer:

The factor that determines the mechanical advantage (or ideal mechanical advantage (IMA) - in the absence of frictional forces) in a simple machine is the ratio perpendicular distance of the applied force to the fulcrum to the perpendicular distance of the load to the fulcrum

The mechanical advantage can therefore by larger than 1 (requiring less force per load), or equal to 1 (effort equal to load) or less than 1( effort more than load)

Explanation:

Answer:

10.44° per sec

Explanation:

Initial angular speed N = 2 rotations per minute

converting to rad/s ω = 2πN/60 = (2 x 3.142 x 2)/60 = 0.21 rad/s

the initial radius of the disk = 16 cm = 0.16 m

final radius = 17 cm = 0.17 m

Angular momentum = [tex]I[/tex]ω

where [tex]I[/tex] = rotational inertia = mass x [tex]radius^{2}[/tex]

ω = angular speed

For the initial case

[tex]I[/tex] = m x [tex]0.16^{2}[/tex] = 0.0256m

Angular momentum = 0.0256m x 0.21 = 0.0054m

For second case

[tex]I[/tex] = m x [tex]0.17^{2}[/tex] = 0.0289m

Angular momentum = 0.0289m x ω = 0.0289mω

For conservation of rotational momentum, initial angular momentum must be equal to the final angular momentum

0.0054m = 0.0289mω

m cancels out, we have

0.0054 = 0.0289ω

ω = 0.187 rad/s

converting back to rpm, we have

N = 0.187/2π = 0.029 rotations per sec

0.029 x 360 = 10.44° per sec

Answer:

(a) The convex mirror image, is always upright at all positions, while images formed by concave mirrors are always inverted when the object distance from the mirror is more than the mirrors focal length.

(b) An upright image is not seen for object at a distance from a concave mirror further than the focal length of the mirror, which is the spoon in the question

Therefore, the location of her eyes of approximately, 30 cm,  from the mirror is more than the mirror's focal length

Explanation: