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2 years ago

Name a chemical that she may use to control this disease

Physics

2 answers:

katrin2010 [14]2 years ago

6 0

Answer:

antisipict -that protact from disese

Deffense [45]2 years ago

3 0

Answer:

Explanation:

Antiseptics, or skin disinfectants, are chemicals for cleaning the skin and wounds. They can kill or prevent the growth of microorganisms.

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What is 2,000m to km

lesantik [10]

Answer: 2km

Explanation:

7 0

3 years ago

Read 2 more answers

Steam is to be condensed on the shell side of a heat exchanger at 150 oF. Cooling water enters the tubes at 60 oF at a rate of 4

zalisa [80]

Answer:

a. 572Btu/s

b.0.1483Btu/s.R

Explanation:

a.Assume a steady state operation, KE and PE are both neglected and fluids properties are constant.

From table A-3E, the specific heat of water is $c_p=1.0\ Btu/lbm.F$ , and the steam properties as, A-4E:

$h_{fg}=1007.8Btu/lbm, s_{fg}=1.6529Btu/lbm.R$

Using the energy balance for the system:

$\dot E_{in}-\dot E_{out}=\bigtriangleup \dot E_{sys}=0\\\\\dot E_{in}=\dot E_{out}\\\\\dot Q_{in}+\dot m_{cw}h_1=\dot m_{cw}h_2\\\\\dot Q_{in}=\dot m_{cw}c_p(T_{out}-T_{in})\\\\\dot Q_{in}=44\times 1.0\times (73-60)=572\ Btu/s$

Hence, the rate of heat transfer in the heat exchanger is 572Btu/s

b. Heat gained by the water is equal to the heat lost by the condensing steam.

-The rate of steam condensation is expressed as:

$\dot m_{steam}=\frac{\dot Q}{h_{fg}}\\\\\dot m_{steam}=\frac{572}{1007.8}=0.5676lbm/s$

Entropy generation in the heat exchanger could be defined using the entropy balance on the system:

$\dot S_{in}-\dot S_{out}+\dot S_{gen}=\bigtriangleup \dot S_{sys}\\\\\dot m_1s_1+\dot m_3s_3-\dot m_2s_2-\dot m_4s_4+\dot S_{gen}=0\\\\\dot m_ws_1+\dot m_ss_3-\dot m_ws_2-\dot m_ss_4+\dot S_{gen}=0\\\\\dot S_{gen}=\dot m_w(s_2-s_1)+\dot m_s(s_4-s_3)\\\\\dot S_{gen}=\dot m c_p \ In(\frac{T_2}{T_1})-\dot m_ss_{fg}\\\\\\\dot S_{gen}=4.4\times 1.0\times \ In( {73+460)/(60+460)}-0.5676\times 1.6529\\\\=0.1483\ Btu/s.R$

Hence,the rate of entropy generation in the heat exchanger. is 0.1483Btu/s.R

4 0

3 years ago

A particular car engine operates between temperatures of 440°C (inside the cylinders of the engine) and 20°C (the temperature of

Step2247 [10]

One of the concepts to be used to solve this problem is that of thermal efficiency, that is, that coefficient or dimensionless ratio calculated as the ratio of the energy produced and the energy supplied to the machine.

From the temperature the value is given as

$\eta = 1-\frac{T_L}{T_H}$

Where,

T_L = Cold focus temperature

T_H = Hot spot temperature

Our values are given as,

T_L = 20\° C = (20+273) K = 293 K

T_H = 440\° C = (440+273) K = 713 K

Replacing we have,

$\eta = 1-\frac{T_L}{T_H}$

$\eta = 1-\frac{293}{713}$

$\eta = 0.589$

Therefore the maximum possible efficiency the car can have is 58.9%

4 0

2 years ago

While an airplane is in flight, four forces act on it. Thrust is caused by the airplane's propellers pushing through the surroun

IceJOKER [234]

The answer would be weight

4 0

3 years ago

Read 2 more answers

A 6.9 kg object is suspended by a string from the ceiling of an elevator. The acceleration of gravity is 9.8 m/s 2 . Determine t

lina2011 [118]

Answer:

Tension, T = 87.63 N

Explanation:

Given that,

Mass of the object, m = 6.9 kg

The string is acting in the upward direction, a = 2.9 m/s²

Acceleration due to gravity, g = 9.8 m/s²

As the lift is accelerating upwards, it means the net force acting on it is given by :

T = m(a+g)

= 6.9 (2.9+9.8)

= 6.9(2.7)

= 87.63 N

So, the tension in the string is 87.63 N.

6 0

2 years ago

Name a chemical that she may use to control this disease​

Name a chemical that she may use to control this disease