Một vô lăng sau khi bắt đầu quay được một phút thì thu được vận tốc 700

Help me with questions 1-8. here's the link to the textbook

Ok so basically I’m here for the points cuz I gotta quiz do in 10 minutes sorry

5 0

3 years ago

A 1.50-m-long rope is stretched between two supports with a tension that makes the speed of transverse waves 48.0 m/s. What are

astra-53 [7]

Answer: a) 16Hz, 3m b) 48Hz, 1mc) 80Hz, 0.6m

Explanation:

a) Fundamental frequency in string is represented as Fo = V/2L where;

Fo is the fundamental frequency

V is the speed of the transverse wave = 48m/s

L is the length of the wire. = 1.50m

Substituting this values in the formula given we have;

Fo = 48/2(1.5)

Fo = 48/3

Fo = 16Hz

The fundamental tone is therefore 16Hz

Using v =f¶

Where f is the frequency and ¶ is the wavelength, the wavelength of the fundamental note will be;

¶ = v/fo

¶ = 48/16 = 3m

b) Overtones or harmonics is the multiple integral of the fundamental frequency. The multiples are I'm arithmetical progression.

First overtone f1 = 2fo

Second overtone f2 = 3fo etc.

Since fo = 16Hz

Second overtone f2 = 3×16 = 48Hz

¶ = v/f2 = 48/48

¶ = 1m

c) Fourth harmonic or overtone will be f4 = 5fo

F4 = 5×16 = 80Hz

The fourth harmonic is therefore 80Hz

¶ = v/f4 = 48/80

¶ = 0.6m

4 0

3 years ago

An automobile engine delivers 55.0 hp. How much time will it take for the engine to do 6.22 × 105 J of work? One horsepower is e

Gennadij [26K]

Answer:

15.2 s

Explanation:

Convert hp to W:

55.0 hp × 746 W/hp = 41,030 W

Power = energy / time

41030 W = 6.22×10⁵ J / t

t = 15.2 s

8 0

3 years ago

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

What is the speed of sound

Charra [1.4K]

Answer:it is 343 meter per second in air.

Explanation:

it is 5 times more in liquids than in gases and 15 times more in solids than in gases.In air it is affected by various physical conditions such as pressure,humidity and temperature.

7 0

3 years ago

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