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3 years ago

9

A Carnot engine takes 3000 J from a reservoir at 600 K, does some work, and discards some heat to a reservoir at 300 K. What is

its efficiency?
50%
60%
20%
30%

1 answer:

exis [7]3 years ago

6 0

Answer: 50%

Explanation: efficiency=power input/power output ×100

Eff.=300/600 ×100

Eff=½×100

Eff=50%

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If 2 electrically charged objects repel one another , which of the statements could be true, one object has more electrons, the

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Both objects have the same electrical charge. Opposite charges attract. And if they were neutral they would not do anything.

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3 years ago

Read 2 more answers

Two identical loudspeakers are placed on a wall 1.00 m apart. A listener stands 4.00 m from the wall directly in front of one of

natita [175]

Answer:

The phase difference is 0.659 rad.

Explanation:

Given that,

Distance between two identical loudspeakers d= 1.00 m

Distance between speakers and listener r= 4.00 m

Frequency = 300 Hz

Suppose we need to find the phase difference in radian between the waves from the speakers when they reach the observer

We need to calculate the r'

Using Pythagorean theorem

$r'=\sqrt{d^2+r^2}$

Where, d = distance between two identical loudspeakers

r = distance between speakers and listener

Put the value into the formula

$r'=\sqrt{(1.00)^2+(4.00)^2}$

$r'=\sqrt{1.00+16.00}$

$r'=4.12\ m$

We need to calculate the path difference

Using formula of path difference

$|r'-r|=4.12-4.00$

$|r'-r|=0.12\ m$

We need to calculate the wavelength

Using formula of wavelength

$\lambda=\dfrac{v}{f}$

Where, v = speed of sound

f = frequency

Put the value into the formula

$\lambda=\dfrac{343}{300}$

$\lambda=1.143\ m$

We need to calculate the phase difference

Using formula of phase difference

$\phi=\dfrac{2\pi\times|r'-r| }{\lambda}$

$\phi=\dfrac{2\pi\times0.12}{1.143}$

$\phi=0.659\ rad$

Hence, The phase difference is 0.659 rad.

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3 years ago

A)what are oxidation numbers? b) what useful functions do oxidation numbers serve

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<span>A) indicate the general distribution of electrons among bonded atoms in molecular compounds
B)</span>useful in naming compounds, writing formulas, and balancing chemical equations
<span>may be used to determine the simplest chemical formula </span>

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3 years ago

The pupil of an eagle’s eye has a diameter of 6.0 mm. Two field mice are separated by 0.010 m. From a distance of 185 m, the eag

max2010maxim [7]

Answer:

time is 5.973826 sec

Explanation:

Given data

diameter D = 6.0 mm 6× $10^{-3}$ m

separated d = 0.010 m

distance (dis) 185 m

speed s = 16 m/s

wavelength = 550 nm = 550 $10^{-9}$ m

to find out

How much time passes

solution

we know that for resolution we use Rayleigh's Criterion i.e

θ = 1.22 wavelength / diameter = separated / distance 1

we calculate distance 1 by put value wavelength, diameter and separated

distance 1 = diameter × separated / 1.22 wavelength

distance 1 = 6× $10^{-3}$ × 0.010 / 1.22 × 550 × $10^{-9}$

distance 1 = 89.418778

so time will be i.e = distance (dis) - distance 1 / speed

time = ( 185 - 89.418778) / 16

time = 5.973826 sec

time is 5.973826 sec

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3 years ago

I need help on 1. B and show work

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Acceleration = (end speed minus beginning speed) divided by (time for the change).

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3 years ago