How many seconds do you need to stop a car going 60 miles per hour, if the pavement is dry?

A rigid tank whose volume is 2 m3, initially containing air at 1 bar, 295 K, is connected by a valve to a large vessel holding a

bazaltina [42]

Answer:

$Q_{cv}=-339.347kJ$

Explanation:

First we calculate the mass of the aire inside the rigid tank in the initial and end moments.

$P_iV_i=m_iRT_i$ (i could be 1 for initial and 2 for the end)

State1

$1bar*|\frac{100kPa}{1}|*2=m_1*0.287*295$

$m_1=232kg$

State2

$8bar*|\frac{100kPa}{1bar}|*2=m_2*0.287*350$

$m_2=11.946$

So, the total mass of the aire entered is

$m_v=m_2-m_1\\m_v=11.946-2.362\\m_v=9.584kg$

At this point we need to obtain the properties through the tables, so

For Specific Internal energy,

$u_1=210.49kJ/kg$

For Specific enthalpy

$h_1=295.17kJ/kg$

For the second state the Specific internal Energy (6bar, 350K)

$u_2=250.02kJ/kg$

At the end we make a Energy balance, so

$U_{cv}(t)-U_{cv}(t)=Q_{cv}-W{cv}+\sum_i m_ih_i - \sum_e m_eh_e$

No work done there is here, so clearing the equation for Q

$Q_{cv} = m_2u_2-m_1u_1-h_1(m_v)$

$Q_{cv} = (11.946*250.02)-(2.362*210.49)-(295.17*9.584)$

$Q_{cv}=-339.347kJ$

The sign indicates that the tank transferred heat to the surroundings.

8 0

2 years ago

Which of the following might be a job or task of an IT worker who manages

-Dominant- [34]

Answer:

I'm pretty sure it's letter d

7 0

2 years ago

Fire andwater ______(do/does) not agree

Elina [12.6K]

Answer:

Hii Dear !!! 

How are you ....

I hope That you are Fine .....

Explanation:

So the answer is __does_____

3 0

2 years ago

Rearrange the formula to make “u” the subject. v - u ——— = t a

solong [7]

Answer:

u = v - a * t

Explanation:

v - u

t = ------

a

v - u = a * t

v - a * t = u

therefore, u = v - a * t

5 0

2 years ago

If a construction company is considering a new type of material to use in their construction, which factors would they

Amanda [17]

I would honestly select every one of the given options. Gor a company evaluating this new material it would be very valuable to hit each of these factors.

4 0

2 years ago