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3 years ago

An increase in speed or velocity can be described as:

Physics

1 answer:

rodikova [14]3 years ago

7 0

Answer:

acceleration

rhymes with accelerator

Explanation:

the increase/decrease or the sudden change in speed and direction of object

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An isobar connects areas of the same _____ _____. An isotherm connects areas of the

WINSTONCH [101]

Hi there!

So, I believe an <em>isobar</em> connects areas of the same atmospheric pressure, and an <em>isotherm</em> connects areas of the same temperature. Hope this helped :)

8 0

3 years ago

A geothermal plant uses geothermal water (yes a liquid) extracted from beneath the Earth using drilling apparatus. The geotherma

leva [86]

To solve this problem it is necessary to apply the concepts of heat change and thermal efficiency.

The heat rate can be expressed under the function

$Q = \dot{m} (h_1-h_2)$

Where,

m = Mass

$h_i =$ Enthalpy at each state

Our values are given as,

$\dot{m} = 200kg/s$

$T_H = 200\°C$

$W = 6000kW$

$T_{H,2} = 90\°C$

$T_L = 25\°C$

From the tables of Enthalpy of Water at 200°C (Saturated liquid state)

$h_1 = 852.4kJ/Kg$

At the same time for 80°C

$h_2 = 334.9kJ/Kg$

Applying the equation of Heat,

$Q = \dot{m}(h_1-h_2)$

Replacing,

$Q = 200*(852.4-334.9)$

$Q = 103500kW$

Therefore the efficiency would be

$\eta = \frac{Q_L}{Q_H}$

$\eta = \frac{6000}{103500}$

$\eta = 0.0579$

Therefore the actual thermal efficiency of the turbine in percent is 0.0579.

6 0

3 years ago

Two loudspeakers emit sound waves along the x-axis. The sound has maximum intensity when the speakers are 19 cm apart. The sound

Vanyuwa [196]

Answer:

Explanation:

The former is the case of constructive interference and the later case relates to destructive interference.

For listener, path difference is the separation of loudspeaker as listener is not standing in between the speaker.

If λ be the wave length

For constructive interference

19 = n λ

For destructive interference

29 = (2n+1) λ / 2

= n λ + λ / 2

= 19 + λ / 2

10 = λ / 2

λ = 20 cm

= 0. 20 m

7 0

3 years ago

A stationary siren emits sound of frequency 1000 Hz and wavelength 0.343 m. An observer who is moving toward the siren will meas

Ainat [17]

Answer:

f>1000Hz and wavelength=0.343 m

Explanation:

We are given that

Frequency of stationary siren,f=1000 Hz

Wavelength of stationary sound, $\lambda=0.343 m$

When a observer is moving towards the siren then the frequency increases.

Therefore,an observer who is moving towards the siren measure a frequency >1000 Hz.

The wavelength depends upon the speed of source.

But we are given that siren is stationary.

Therefore, source is not moving and then the wavelength remains same.

f>1000Hz and wavelength=0.343 m

4 0

3 years ago

The 1000-lb elevator is hoisted by the pulley system and motor M. If the motor exerts a constant force of 500 lb on the cable, d

Nezavi [6.7K]

Answer:

the power that must be supplied to the motor is 101.45 hp

Explanation:

Given that,

The weight of elevator = 1000lb

The motor exerts a constant force of 500 lb on the cable

The load has been hoisted s = 15 ft starting from rest

The motor has an efficiency of e = 0.65

According to the equation of motion:

F = ma

$3(500) - 1000 = \frac{1000}{32.2} * aa = 16.1 ft/s^2$

$v^2 - u^2 = 2a (S - So)\\\\v^2 - (0)^2 = 2 * 16.1 (15-0)\\\\v = 21.98m/s$

To calculate the output power:

P(out) = F. v

P(out) = 3 (500) * 21.98

P(out) = 32970 lb.ft/s

As efficiency is given and output power is known, we can calculate the input power.

ε = P(out) / P(in)

0.65 = 32970 / P(in )

P(in) = 50,723 lb.ft/s

P(in) = 50,723 / 500 hp

= 101.45 hp

the power that must be supplied to the motor is 101.45 hp

5 0

4 years ago