Which of the following is an example of convection?
A
heating an iron pipe by placing it into a fire

B
warming one's hands by rubbing them together

C
melting an ice cube in a microwave

D
heating water to a rolling boil

Answers

Answer 1

Answer:

D. Heating water to a rolling boil


Related Questions

A force of 30 newtons and a force of 20 newtons act
concurrently on an object. Which of the following
resultant forces could be produced using these two
forces?

Answers

Answer: (2): 25 N.

Explanation:

We know that two forces act concurrently on the same object.

One force has a magnitude of 30 N, so the first force can be written as:

F = (fx, fy) such that:

30N = √(fx^2  + fy^2)

And other force of 20 N, let's call it G.

G = (gx, gy)

Such that:

20 N = √(gx^2 + gy^2)

Now, the maximum possible resultant force is when both forces point in the same direction.

Then we can directly add them; G + F = 20N + 30N = 50N

And the minimum resultant force is when both forces point in opposite directions, then we can directly subtract: F - G = 30N - 20N = 10N.

Then the resultant force, F', will be:

10N ≤ F' ≤ 50N.

The only option in that range is the second option, (2) 25N.

The resultant force produced by the two concurrent forces is 50 N.

The given parameters;

first coplanar force, F₁ = 30 Nsecond coplanar force, F₂ = 20 N

Concurrent forces, are forces acting at a point and the resultant of such forces is a single force when acting alone will balance the effect of the concurrent forces.

[tex]F_3 = F_1 + F_2[/tex]

where;

F₃ is the resultant force

[tex]F_3 = 30 \ N \ + \ 20 \ N\\\\F_3 = 50 \ N[/tex]

Thus, the resultant force produced by the two concurrent forces is 50 N.

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Question 7 (2 points)
Rachel performed an experiment testing the hours students slept with their
performance on a test. In this experiment, the hours that they slept was the_____ variable, while the grade they got on
the test was the
_____ variable.

Answers

This has to do with independent and dependent variables. The independent variable is what affects the dependant variable, so the question is, does a students mark on a test affect their hours of sleep or does their hours of sleep affect their test results? Which one makes more sense? I would say the latter.

When a25 kg crate is pushed across a frictionless horizontal floor with a force of 200n directed 20°below the horizontal, magnitude of the normal force of the floor on the crate is

Answers

Answer:

310N

Explanation:

These are the options for the question

A)68N

B. 68N

C. 180N

D. 250N

the normal force of the floor on the crate can be calculated using below formula

N=W+ Fsin(x)

= mg+ Fsin(x)

m= mass of the crate= 25kg

g= acceleration due to gravity= 9.8m/s^2

We were told a force of 200n directed 20°below the horizontal

Which means angle(x)= 20°

We were given horizontal floor with a force of 200N I.e F= 200N

If we substitute these values into the formula above we have

N=mg+ Fsin(x)

= (25kg×9.8) + 200sin(20)

=313.5N

Hence, the the magnitude of the normal force of the floor on the crate is approximately 310N

CHECK THE ATTACHMENT FOR THE DIAGRAM

NEED HELP NOW. I WILL BRAINLIEST

Answers

Answer:

number of Protons=16

number of Neutrons=16

number of electrons=32

Explanation:

Tip:-

Always the number of protons = the number of neutrons.

Add them and you will get the number of electrons.

Happy to help

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. Calculate the kinetic energy of a 0.25-kg toy car traveling at a
constant velocity of 2 m/s.

Answers

See the attachment....

The kinetic energy of the toy car is 0.50 Joules.

Given the following data:

Mass of toy car = 0.25 kg Velocity = 2 m/s.

To find the kinetic energy of the toy car:

Kinetic energy is an energy that is possessed by a physical object or body due to its motion.

Mathematically, kinetic energy is calculated by using the formula;

[tex]K.E = \frac{1}{2} MV^2[/tex]

Where:

K.E is the kinetic energy. M is the mass of an object. V is the velocity of an object.

Substituting the given parameters into the formula, we have;

[tex]K.E = \frac{1}{2} \times 0.25 \times 2^2\\\\K.E = \frac{1}{2} \times 0.25 \times 4\\\\K.E =0.25 \times 2[/tex]

K.E = 0.50 Joules

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What is required to make a resting object move or a moving object change its speed or direction?

Answers

Answer:

of a moving object?

Any change of speed or direction requires a force. In other words, forces cause acceleration. The direction in which an object moves depends on the direction of the force that is applied to the object. If there is more than one force, the forces work together

A 73-kg Norwegian olympian ski champion is going down a hill sloped at 39 ◦ . The coefficient of kinetic friction between the skis and the snow is 0.15. a. How fast is the skier going 5.0 s after starting from rest? b. After the Norwegian skier has been moving for 5.0 s, the friction of the snow suddenly increased making the net force on the skier zero. What is the new coefficient of friction? c. How fast would the skier now be going after skiing for 5.0s?

Answers

Answer:

Explanation:

net force on the skier = mg sin 39 - μ mg cos39

mg ( sin39 - μ cos39 )

= 73 x 9.8 ( .629 - .116)

= 367 N

impulse = net force x time = change in momentum .

= 367 x 5 = 1835 kg m /s

velocity of the skier after 5 s = 1835 / 73

= 25.13 m /s

b )

net force becomes zero

mg ( sin39 - μ cos39 ) = 0

μ = tan39

= .81

c )

net force becomes zero , so he will continue to go ahead with constant speed of 25.13 m /s

so he will have speed of 25.13 m /s after 5 s .

3. Michelle failed her most recent exam, which has
brought her class grade down to a D. The
semester is ending in 2 weeks and she has 1
assignment and 1 quiz left to make up for the
class. She sets the goal to do well on both so that
those will improve her class grade. Which of the
following SMART goal components is her goal
missing?(This is physical education)
a. The goal is not specific
b. The goal is not important
c. The goal is not relevant
d. The goal is not timely

Answers

the goal is not specific. you want to make a specific goal so u know how to reach it

Why is an important to come up with a plan for how are you to respond to negative peer pressure before the situation happens
A: it is hard to refuse in the situation if you have not decided how you would handle it ahead of time

B: because it is very likely you will face these situation in the future

C: both a and b

Answers

Answer:

C ( is hard to refuse in the situation if you have not decided how you would handle it ahead of time

B: because it is very likely you will face these situation in the future)

Find deacceleration An engineer in a locomotive sees a car stuck on the track at a railroad crossing in front of the train. When the engineer first sees the car, the locomotive is 360 m from the crossing and its speed is 16 m/s. If the engineer’s reaction time is 0.53 s, what should be the magnitude of the minimum deceleration to avoid an accident? Answer in units of m/s^2

Answers

Answer:

The deceleration is  [tex]a = -0.7273 \ m/s^2[/tex]  

Explanation:

From the question we are told that

  The distance of the car from the crossing is [tex]d = 360 \ m[/tex]

   The speed is [tex]u = 16 \ m/s[/tex]

    The reaction time of the engineer is  [tex]t = 0.53 \ s[/tex]

Generally the distance covered during the reaction time is  

      [tex]d_r = u * t[/tex]

=>   [tex]d_r = 16 * 0.53[/tex]

=>   [tex]d_r = 8.48 \ m[/tex]

Generally distance of the car from the crossing after the  engineer reacts is

      [tex]D = d- d_r[/tex]        

=> [tex]D = 360 - 8.48[/tex]      

=> [tex]D = 352 \ m[/tex]

Generally from kinematic equation

      [tex]v^2 = u^2 + 2as[/tex]

Here v is the final velocity of the car which is  0 m/s

So

        [tex]0^2 = 16^2 + 2 * a * 352[/tex]

=>    [tex]a = -0.7273 \ m/s^2[/tex]  

3. 500ml of 60oC water at is added to a beaker. Water’s specific heat is 4.186 J/g °C. You have 40ml of and unknown substance that you add to the same beaker. The unknown substance’s specific heat is 14.3/goC The final temperature of the beaker is 45oC. What was the initial temperature of the unknown substance?

Answers

Idkd djdjdbd djkdmdkdmkrkr r r r. R r

What is the difference between a structural and inflation Epoch? (big bang eras)

Answers

Answer:  the difference between a Structure is from the Latin word structura which means "a fitting together, building." Although it's certainly used to describe buildings, it can do more than that and a In physical cosmology the inflationary epoch was the period in the evolution of the early universe when, according to inflation theory, the universe underwent an extremely rapid exponential expansion.

Explanation:

What net force is necessary to keep a 1.0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

Answers

Answer:

8.0 N

Explanation:

A dog chases a skateboarder travelling at 10.4\,\dfrac{\text{m}}{\text{s}}10.4 sm ​ 10, point, 4, start fraction, start text, m, end text, divided by, start text, s, end text, end fraction. The skateboarder speeds up with a constant acceleration for 39\,\text{m}39m39, start text, m, end text over 3.3\,\text{s}3.3s3, point, 3, start text, s, end text. We want to find the acceleration of the skateboarder over the 3.3\,\text{s}3.3s3, point, 3, start text, s, end text time interval

Answers

Answer:Δx=v0t + 1/2 at 2


How long would it take a car going 25 m/s to travel 1000 meters?

Answers

Answer:

40

Explanation:

1000 divided by 25 is 40

A 10.0 kg box is dragged 5.00 meters across a rough horizontal floor by a rope with a tension
of 45.0 N that makes an angle of 20.0 degrees to the horizontal. If the box started with a
speed of 3.00 m/s and ended with a speed of 5.00 m/s, what was the NET work done on the
box?

Answers

Answer:

Explanation:

Net work done on the box = increase in kinetic energy

= 1 / 2 x 10 ( 5² - 3² )

= 80 J .

As shown in the diagram below, a rope attached to a 500.-kilogram crate is used to exert a force of 45 newtons at an angle of 65 degrees above the horizontal. The horizontal component of the force acting on the crate is:

1) 19N
2) 41N
3) 210N
4) 450N

Answers

Answer:

19N

Explanation:

Sorry i don’t really know why that’s the answer just that i know thats correct. so what the thing i looked up said

45N(cosine65)= horizontal component

45N(0.423)=19N and that’s the answer

i don’t know where the .423 came from but i hoped i helped :)

Answer: 1

Explanation:

Given

Mass of Crate [tex]m=500\ kg[/tex]

Applied force [tex]F=45\ N[/tex] at an angle of [tex]\theta=65^{\circ}[/tex]

The applied force can be resolved in to two direction i.e. vertical and horizontal direction.

From the figure, horizontal component of the force is [tex]F\cos 65^{\circ}[/tex]

[tex]\Rightarrow F\cos65^{\circ}=45\cos 65^{\circ}\\\\\Rightarrow 19.017\approx 19\ N[/tex]

Thus, the horizontal component of force is [tex]\mathbf{19\ N}[/tex]

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A coin was flipped in the air and reached a maximum height of 1.5 meters. What was the initial velocity? How long was the coin in the air? Ignore air resistance.

Answers

Answer:

Vi = 5.42 [m/s]

t = 0.55 [s]

Explanation:

To solve this problem we must use the following equation of kinematics.

[tex]v_{f} ^{2} =v_{o} ^{2} -(2*g*y)[/tex]

where:

Vf = final velocity = 0 (At maximum elevation the coin doesn't move)

Vi = initial velocity [m/s]

g = gravity acceleration = 9.81 [m/s²]

y = elevation = 1.5 [m]

Note: The negative sign in the above equation means that the direction of the gravity acceleration is acting against the movement of the coin when it is going up.

0 = (Vi)² - (2*9.81*1.5)

29.43 = (Vi)²

Vi = 5.42 [m/s]

The time we can find it using the next equation also from kinematics.

[tex]v_{f} =v_{i} -g*t\\[/tex]

0 = 5.42 - 9.81*t

t = 5.42/9.81

t = 0.55 [s]

Answer:

Vi = 5.42 [m/s]

t = 0.55 [s]

Explanation:

To solve this problem we must use the following equation of kinematics.

where:

Vf = final velocity = 0 (At maximum elevation the coin doesn't move)

Vi = initial velocity [m/s]

g = gravity acceleration = 9.81 [m/s²]

y = elevation = 1.5 [m]

Note: The negative sign in the above equation means that the direction of the gravity acceleration is acting against the movement of the coin when it is going up.

0 = (Vi)² - (2*9.81*1.5)

29.43 = (Vi)²

Vi = 5.42 [m/s]

The time we can find it using the next equation also from kinematics.

0 = 5.42 - 9.81*t

t = 5.42/9.81

t = 0.55 [s]

Explanation:

Hi Kema :3


A resistor converts 350 J of electrical energy to other forms of energy. What is the amount of
charge that flows through it when a potential difference of 7 V is applied across it?​

Answers

Answer:

50C

Explanation:

Given parameters:

Electrical energy  = 350J

Potential difference  = 7V

Unknown:

Amount of charge = ?

Solution:

To solve this problem, use the expression below;

  E  = q x v

E is the electrical energy

q is the quantity of charge

v is the voltage

Insert the parameters and solve for q;

            350 = q x 7

            q = [tex]\frac{350}{7}[/tex]

             q = 50C

The value of the charge will be 50 C. A charge is something experienced as a force in the electric and megnetic field.

what is the charge?

When the matter is put in an electromagnetic field, it has an electric charge, which causes it to experience a force. A positive or negative electric charge can exist.

Charges that are similar repel each other, whereas charges that are dissimilar attract each other. The term "neutral" refers to an item that has no net charge.

The given data in the problem is;

e is the electrical energy  = 350J

V  is the Potential difference  = 7V

q is the charge=?

[tex]\rm e = qV \\\\ \rm q=\frac{e}{V} \\\\ \rm q=\frac{350 }{7} \\\\ \rm q= 50 \ C[/tex]

Hence the value of the charge will be 50 C.

To learn more about the charge refer to the link;

https://brainly.com/question/24391667

A child kicks a ball with an initial velocity of 8.5 meters per second at an angle of 35.00 degrees above the horizontal. The ball has an initial vertical velocity of 4.9 meters per second and a total time of flight of 1.0 second. The horizontal component of the ball's initial velocity is approximately

Answers

Answer:

6.96 m/s

Explanation:

Horizontal component = V cos α

V= initial velocity of the ball= 8.5 m/s

α = 35°

Horizontal component = 8.5 cos35 = 6.96 m/s

Therefore, the horizontal component of the balls initial velocity is 6.96 m/s

This question involves the concepts of projectile motion, Pythagora's theorem, and the horizontal and vertical components of velocity.

The horizontal component of the ball's initial velocity is "6.94 m/s".

This is an example of a projectile motion with both the horizontal and vertical components of the velocity. The resultant velocity, in this case, can be found using Pythagora's theorem.

[tex]v^2=v_x^2+v_y2[/tex]

where,

v = resultant speed = 8.5 m/s

vx = horizontal component of speed = ?

vy = vertical component of speed = 4.9 m/s

Therefore,

[tex](8.5\ m/s)^2=v_x^2+(4.9\ m/s)^2\\\\v_x=\sqrt{(8.5\ m/s)^2-(4.9\ m/s)^2}\\\\v_x=6.94\ m/s[/tex]

Learn more about Pythagora's Theorem here:

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The attached picture shows the Pythagora's theorem.

7. How fast is Michael accelerating if his mass is 10 kg and he is exerting
1,500 Newtons of force?

Answers

Answer:

150 m/s²

Explanation:

Plz like

Answer:

150 m/s²

Explanation:

a car can accelerate from rest to 70 km/s in 7 seconds. what is the cars average acceleration. show your work

Answers

Answer:

10km/s²

         

Explanation:

Given parameters:

Initial velocity  = 0km/s

Final velocity = 70km/s

Time  = 7s

Unknown:

Acceleration =?

Solution:

Acceleration is the rate of change of velocity with time.

It is mathematically expressed as;

      A = [tex]\frac{v - u}{t}[/tex]  

v is the final velocity

u is the initial velocity

 t is the time

       A  = [tex]\frac{70 - 0}{7}[/tex]   = 10km/s²

         

Lucy needs to lift a crate to a shelf 20 m high. She does 12,000 J of work on a machine to help her. The machine exerts a force of 500 N to lift the crate.

Answers

Answer:

83.34%.

Explanation:

Given that,

Lucy does 12,000 J of work on a machine to help her

The machine exerts a force of 500 N to lift the crate.

Height of the shelf = 20 m

We need to find the efficiency of the machine. The ratio of output work to the input work is called the efficiency of any machine. It is given by :

[tex]\eta=\dfrac{W_o}{W_i}\times 100\\\\=\dfrac{500\times 20}{12000}\\\\=83.34\%[/tex]

So, the efficiency of the machine is 83.34%.

Answer:

83%

Explanation:

just took quiz on connections acadmy

A _________ is a turning effect caused by a force.

Answers

Answer:

[tex]{\boxed{ \underline{ \sf{Moment \: of \: force}}}}[/tex]

✎ A moment of force is a turning effect caused by a force.

Explanation :

When force is exerted on a body , it results either in displacement of the body or its rotation about a point or axis i.e the rotation of turning effect of force. The turning effect of force acting on a body about an axis is called moment of the force. It may be clockwise or anti - clockwise.

Hope I helped!

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In the long run, people who practice self-regulation through physical exercise and time-managed programs experience an increase in

Answers

Answer:

Self control

Explanation:

Self control involves individuals having a strong discipline towards certain conditions. The conditions could be cravings for something or other forms of activities.

Self control is usually developed by people who practice self-regulation through physical exercise and time-managed programs experience as they have been known to bring about an increase in it.

a force of 200N is being applied over an area measuring 0.75m^2

Answers

Answer:

357KG

Explanation:

A motorcyclist travelling at 30m/s starts to apply his brake when he is 50m from the traffic light that has just turned red .if he reached the traffic light. what is the deceleration

Answers

80 because if you add 50 +30 =80 so yea that why I pick 80

Sonia's grandfather was not able to see clearly after returning from his walk on a bright sunny day. He was about to hit a chair when sonia held him and guided him to the nearby sofa. What could be the reason for sonia's grandfather not being able to see clearly on entering the house

Answers

Answer:

Sonia's grandfather was not able to see clearly after returning from his walk on a bright sunny day. He was about to hit a chair when Sonia held him and guided him to the nearby sofa, in sunny environment grandfather's eye is set according to high brightness, his pupils become small to lower the number of light rays entering his eye, when he returned from sunny environment to his house which was having low brightness so the pupils should enlarge to absorb more light to see clearly but due to old age his Ciliary muscle of the eye would have worn out and due to this poor coordination the image was not clear.

At highway speeds a car can accelerate at 1.7 m/s2.
At this rate how long does it take to accelerate from
23.6 m/s to 27.8 m/s?

Answers

Answer: 2.5 seconds

Explanation:

We know that the acceleration is:

a(t) = 1.7 m/s^2

To get the velocity function, we must integrate over time, and we will get:

v(t) = (1.7m/s^2)*t + v0

Where v0 is the initial velocity, in this case, we assume that we start at 23.6m/s, then the initial velocity is:

v0 = 23.6 m/s

Then the velocity equation is:

v(t) =  (1.7m/s^2)*t + 23.6 m/s

Now we want to find the value of t such v(t) = 27.8 m/s

Then:

v(t) =  27.8 m/s =  (1.7m/s^2)*t + 23.6 m/s

        27.8 m/s  - 23.6 m/s =  (1.7m/s^2)*t

         4.2 m/s = (1.7m/s^2)*t

         4.2m/s/(1.7m/s^2) = t = 2.5 s

Then at that acceleration, you need 2.5 seconds.

What is the amount of solvent in an amount of solute?

Answers

Answer:

The concentration of a solution is a measure of the amount of solute that has been dissolved in a given amount of solvent or solution. A concentrated solution is one that has a relatively large amount of dissolved solute. A dilute solution is one that has a relatively small amount of dissolved solute.

Explanation:

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Writing an Argumentative Essay about Fire Prevention According to Article III of the Constitution, who may establish lower courts?Athe CongressBthe presidentthe Supreme CourtDthe individual states Alexandra has two articles about social media consumption, one from 2007 and one from 2018, that she could include in her research about social media and addiction. Which one may be the more appropriate article, according to the CRAAP analysis? One tank is filling at a rate of 4/5 gallon per 1/2 minute. A second tank is filling at a rate of 7/8 gallon per 1/2 minute. Which tank is filling faster? Label each table as linearor non-linear.A. input:1,2,3,4,output: 0,2,6,12B) input; -2,0,2,4output: 4,2,0,-2c) input: -3,-2,-1,0output: 5,3,-1,1d) input: -4,0,4,8output: 1,4,9,16IT IS DUE TODAY I NEED HELP According to the United Nations, this is a deliberate and systematic destruction (or planning of destruction), in a whole or in part, of an ethnic, racial, religious, or national group. If someone traveled through time and went back before they were born, would they still see find themself? what is 6/a-6 = 3/a-3 ?help me please Answer this question correctly Select all of the ratios that are equivalent to 6:3 *2:112:63:630:156:612:9 help what's the answer? 7+1=? Qu hay? Cuaderno 3Adnde vas?Ejercicio 8Completa las frases con la formacorrecta del verbo ir.1. Nosotros______al parque.2. Adnde_______t?3. Yo______ al cine4. Cmo_______Vd. al colegio,seor Martn?5.mis Padres______de compras el sbado 6.laura_________a case de sus amigas7.vds_________ muy rpido8.el profesor_________ al aula An allele whose trait is masked (weaker) in the presence of a stronger allele As invasive species, how does the introduction of the feral pig and the water hyacinth impact an ecosystem? (Site 1) A 1000-kg car is travelling at 30 m/s (about 67 mph, for context). What is the car's momentum? If the driver then slams on the brakes, applying a force of 7,500 N, how long will it take the car to stop? Can you list 4 facts about French markets and specialty stores? WHAT IS THE L WORD FROM SID THE SLOTH! Brian orders a center pivot irrigation system to water his field system is made up of a line connected pipes that turn around a center point Brian system will be 1000 150 feet long what is the longest distance across the space the system still water show your work 4. How did European exploration and settlement affect American Indians? CHOOSE TWO. A. American Indians became an essential part of European society. B. They suffered a population decrease due to conflict and disease. C. They gained wealth by aiding explorers in search of gold. D. They finally learned the skills required to rule themselves. E. Their cultural practices changed, sometimes involuntarily. Tom Skinner has $45,000 invested in a stock with a beta of 0.8 and another $55,000 invested in a stock with a beta of 1.4. These are the only two investments in his portfolio. What is his portfolio's beta?