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3 years ago

12

The reason lines on the bottom of a swimming pool can look wavy when seen from above is that

1 answer:

masha68 [24]3 years ago

3 0

Answer:

it is under water

Explanation:

You might be interested in

What are some of the phenotypic plant traits that scientists are investigating? Why do you think these traits were chosen?

vodomira [7]

The term phenotype in a more specific context to describe the collective expression of the genotype in conjunction with the environment on a plant's observable characteristics.

<u>Explanation</u>:

Phenotype, any of the measurable features of an organism arising from its genotype association (total genetic inheritance) with the environment. Behaviour, biochemical properties, colour, form, and scale are examples of measurable characteristics.
An allele is another type of one gene. A phenotype triggered by the expression of a gene or group of genes is the external manifestation of a human trait.
A trait is an attribute unique to an organism. The genotype's external expression is called the phénotype.

8 0

3 years ago

A 63-kg hiker is climbing the 828-m-tall Burj Khalifa in Dubai. If the efficiency of converting the energy content of the bars i

konstantin123 [22]

Answer:

$T_f=5854.76$ °C

Explanation:

Given:

mass of hiker, m= 63 kg

height to be climbed, h= 828 m

energy produced by an energy bar, $E= 1.10\times 10^6 J$

heat capacity of the hiker, $c=75.3 J.mol^{-1}.K^{-1}= 4.184 J.kg^{-1}.K^{-1}$

initial body temperature of hiker, $T_i=36.6 \degree C$

<em>The efficiency of converting the energy content of the bars into the work of climbing is 25%, the remaining 75% of the energy released through metabolism is heat released to her body.</em>

We find the energy required for climbing 828 m height:

W=m.g.h

$W=63\times 9.8\times 828$

W= 511207.2 J

∵Hike eats 2 energy bars= $2\times 1.1\times 10^{6} J$

Energy produced $= 2.2\times 10^{6} J$

Now, according to her efficiency:

Total energy required for producing the work of W= 511207.2 J which is required to climb the given height will be (say, E):

$25\% of E= 511207.2$

$\Rightarrow E= 511207.2\times \frac{100}{25}$

$E=2044828.8 J$

&

Amount of total energy (E) converted into heat(Q) is:

$Q=2044828.8-511207.2\\Q=1533621.6J$

As we know that:

heat, $Q=m.c. (T_f-T_i)$ .................(1)

where:

$T_f$ is the final temperature

Putting respective values in the eq. (1)

$1533621.6= 63\times 4.184\times (T_f-36.6)$

$(T_f-36.6)\approx 5818.16$

$T_f\approx 5854.76$ °C

4 0

3 years ago

Under which of the following circumstances do neap tides occur?

Yakvenalex [24]

I think <span>its C
hope it helps

</span>

4 0

4 years ago

Read 2 more answers

A cave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. The lift i

Leya [2.2K]

Answer:

a) 323.4J

b) 0J

c) -323.4J

Explanation:

a) W=Fd

F=ma

solve for acc. using kinematics

v^2=vo^2+2a(x)

8.41=2a(12)

4.205=a(12)

0.35=a

F=(77)(0.35)

F=26.95N

W=26.95*12...... W=323.4J

b) No acceleration, thus no force, thus no work!

c) W=Fd

F=ma

find acc. using kinematics: v^2=vo^2+2a(x)

0=(2.9^2)+2a(12)

0=8.41+2a(12)

-8.41=2a(12)

-4.205=a(12)

-0.35=a

F=(77)(-0.35)

F=-26.95N

W=(-26.95)(12)

W=-323.4J

Yes, work can be negative!

5 0

3 years ago

A sound has 13 crests and 15 troughs in 3 seconds. When the second crest is produced the first is 2cm away from the source? Calc

Yuki888 [10]

Answer:

The wavelength will be 4 cm, frequency will be 4.66 Hz and wave speed is 18.6 cm/sec

Explanation:

Given:

No. of crest = 13

No. of trough = 15

Time = 3 seconds

Hence, 1 crest or 1 trough = $\frac{1}{2}\lambda$

therefore,

13 C + 15 T = $28(\frac{1}{2}\lambda)$

= $14\lambda$

Time given 3 seconds

= $\frac{3}{14}s$

$\nu= \frac{14}{3}$

$\nu= 4.6 Hz \approx 5 Hz$

2 cm distance is travelled is time period

$\lambda = 4 cm$

Again wave will travel in 1 T = 4 cm

wave speed v = $\lambda\times\nu$

= $4\times\frac{14}{3}$

= 18.6 cm/s

5 0

3 years ago