1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
jek_recluse [69]
3 years ago
6

A student drops two metallic objects into a 120-g steel con- tainer holding 150 g of water at 25°C. One object is a 200-g cube o

f copper that is initially at 85°C, and the other is a chunk of aluminum that is initially at 5.0°C. To the surprise of the student, the water reaches a final temperature of 25°C, precisely where it started. What is the mass of the aluminum chunk?
Physics
1 answer:
marissa [1.9K]3 years ago
7 0

Answer:

The mass of the aluminum chunk is 258 g

Explanation:

Given;

mass of steel container =  120-g

mass of water = 150 g

initial temperature of water, = 25°C

mass of copper cube, M_{cu} = 200 g

initial temperature of the copper cube, T_c_u = 85°C

initial temperature of the aluminum chunk T_A_l = 5.0°C

Neglecting heat loss, heat exchanged by the two metallic objects is the same since initial temperature is equal to final temperature of water.

M_{Al}C_{Al} \delta T_{Al} = M_{cu}C_{cu} \delta T_{cu}

where;

C_{AL} is specific heat capacity of aluminum

\delta T_{Al} is change in temperature of aluminum

C_c_u is the specific heat capacity of copper

\delta T_c_u is the change in temperature of copper

M_{Al}C_{Al} \delta T_{Al} = M_{cu}C_{cu} \delta T_{cu} \\\\M_{Al} = \frac{M_{cu}C_{cu} \delta T_{cu}}{C_{Al} \delta T_{Al}} \\\\M_{Al} = \frac{0.2*387*60}{900*20} = 0.258 \ kg

Therefore, the mass of the aluminum chunk is 258 g

You might be interested in
If a circuit has a power of 50 W with a current of 4.5 A, what is the resistance in the circuit?
lawyer [7]

Answer:

{ \rm{power, \: p = current \times p.d}} \\ { \rm{50 = 4.5 \times (current \times resistance)}} \\ { \rm{50 = 4.5 \times (4.5 \times r)}} \\ { \rm{resistance =  \frac{50}{ {4.5}^{2} } }} \\  \\ { \rm{resistance = 2.5 \:  ohms}}

8 0
1 year ago
During the middle of a family picnic, Barry Allen received a message that his friends Bruce and Hal
weeeeeb [17]

The kinematics of the uniform motion and the addition of vectors allow finding the results are:

  • The  Barry's initial trajectory is 94.30 10³ m with n angles of θ = 138.8º
  • The return trajectory and speed are v = 785.9 m / s, with an angle of 41.2º to the South of the East

Vectors are quantities that have modulus and direction, so they must be added using vector algebra.

A simple method to perform this addition in the algebraic method which has several parts:

  • Vectors are decomposed into a coordinate system
  • The components are added
  • The resulting vector is constructed

 Indicate that Barry's velocity is constant, let's find using the uniform motion thatthe distance traveled in ad case

              v = \frac{\Delta d}{t}

              Δd = v t

Where  v is the average velocity, Δd the displacement and t the time

We look for the first distance traveled at speed v₁ = 600 m / s for a time

          t₁ = 2 min = 120 s

          Δd₁ = v₁ t₁

          Δd₁ = 600 120

          Δd₁ = 72 10³ m

Now we look for the second distance traveled for the velocity v₂ = 400 m/s    

  time t₂ = 1 min = 60 s

          Δd₂ = v₂ t₂

          Δd₂ = 400 60

          Δd₂ = 24 103 m

   

In the attached we can see a diagram of the different Barry trajectories and the coordinate system for the decomposition,

We must be careful all the angles must be measured counterclockwise from the positive side of the axis ax (East)

Let's use trigonometry for each distance

Route 1

          cos (180 -35) = \frac{x_1}{\Delta d_1}

          sin 145 = \frac{y_1}{\Delta d1}

          x₁ = Δd₁ cos 125

          y₁ = Δd₁ sin 125

          x₁ = 72 103 are 145 = -58.98 103 m

          y₁ = 72 103 sin 155 = 41.30 10³ m

Route 2

          cos (90+ 30) = \frac{x_2}{\Delta d_2}

          sin (120) = \frac{y_2}{\Delta d_2}

          x₂ = Δd₂ cos 120

          y₂ = Δd₂ sin 120

          x₂ = 24 103 cos 120 = -12 10³ m

           y₂ = 24 103 sin 120 = 20,78 10³ m

             

The component of the resultant vector are

              Rₓ = x₁ + x₂

              R_y = y₁ + y₂

              Rx = - (58.98 + 12) 10³ = -70.98 10³ m

              Ry = (41.30 + 20.78) 10³ m = 62.08 10³ m

We construct the resulting vector

Let's use the Pythagoras' Theorem for the module

             R = \sqrt{R_x^2 +R_y^2}

             R = \sqrt{70.98^2 + 62.08^2}   10³

             R = 94.30 10³ m

We use trigonometry for the angle

             tan θ ’= \frac{R_y}{R_x}

             θ '= tan⁻¹ \frac{R_y}{R_x}

             θ '= tan⁻¹ \frac{62.08}{70.98}

             θ ’= 41.2º

Since the offset in the x axis is negative and the displacement in the y axis is positive, this vector is in the second quadrant, to be written with respect to the positive side of the x axis in a counterclockwise direction

            θ = 180 - θ'

            θ = 180 -41.2

            θ = 138.8º

Finally, let's calculate the speed for the way back, since the total of the trajectory must be 5 min and on the outward trip I spend 3 min, for the return there is a time of t₃ = 2 min = 120 s.

The average speed of the trip should be

             v = \frac{\Delta R}{t_3}  

             v = \frac{94.30}{120}  \ 10^3

              v = 785.9 m / s

in the opposite direction, that is, the angle must be

               41.2º to the South of the East

In conclusion, using the kinematics of the uniform motion and the addition of vectors, results are:

  • To find the initial Barry trajectory is 94.30 10³ m with n angles of  138.8º
  • The return trajectory and speed is v = 785.9 m / s, with an angle of 41.2º to the South of the East

Learn more here:  brainly.com/question/15074838

4 0
2 years ago
In the context of energy transfers with hot and cold reservoirs, the sign convention is that _______________.
Likurg_2 [28]

Answer:

B. QC > 0; QH < 0

Explanation:

Given that there are two reservoir of energy.

Sign convention for heat and work :

1.If the heat is adding to the system then it is taken as positive and if heat is going out from the system then it is taken as negative.

2. If the work is done on the system then it is taken as negative and if the work is done by the system then it is taken as positive.

From hot reservoir heat is going out that is why it is taken as negative

Q_H

From cold reservoir heat is coming inside the reservoir that is why it is taken as positive

Q_C>0

That is why the answer will be

Q_H ,Q_C>0

8 0
3 years ago
What is the current that reverses direction in a regular patter called
Oxana [17]

Answer:

Current that reverses direction in the regular pattern is called an alternating current, abbreviated as 'AC'.

Explanation:

hope this helps!

4 0
3 years ago
An oil slick on water is 120 nm thick and illuminated by white light incident perpendicular to its surface. What color does the
gregori [183]

Answer:

\lambda = 672 nm

so this is nearly red colour light

Explanation:

As we know that the interference of light from reflected light then the path difference is given as

\Delta x = 2\mu t + \frac{\lambda}{2}

now we know that for constructive interference of light the path difference is given as

\Delta x = n\lambda

so we will have

2\mu t + \frac{\lambda}{2} = N\lambda

so we will have

4\mu t = \lambda

\lambda = 2(1.40)(120nm)

\lambda = 672 nm

so this is nearly red colour light

8 0
3 years ago
Other questions:
  • Which of the following is created when the ice of a comet starts to melt into gases?
    12·1 answer
  • Physics multiple choice
    11·2 answers
  • How much heat must be added to make a 5g substance with a specific heat of 2 J/gC that has its temperature go up 10 degrees? Q =
    12·1 answer
  • Which phrase best describes sir isaac newton's contributions to modern science and therefore to the industrial revolution?
    14·1 answer
  • At a particular instant, a moving body has a kinetic energy of 295 J and a momentum of magnitude 25.1 kg · m/s.(a)What is the sp
    13·1 answer
  • Large electric fields in cell membranes cause ions to move through the cell wall. The field strength in a typical membrane is 1.
    5·1 answer
  • Determine which of the following moving objects obey the equations of projectile motion developed in this topic. A ball is throw
    5·1 answer
  • How does the mass of an object affect the outcome when an unbalanced force acts on it?
    14·1 answer
  • Save
    7·1 answer
  • URGENT PLEASE HELP!!!! GIVING BRAINLIEST!! If you answer this correctly ill answer some of your questions you have posted! (60pt
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!