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3 years ago

Why does a solid change to liquid when heat is added

1 answer:

8 0

heat excites molecules at their "lattice" sites. Enough to break the lattice bonds set the molecules free of each other and ... melt.

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Please Help Me!!!........

-Dominant- [34]

Answer:

Explanation:

3 0

3 years ago

You are the science officer on a visit to a distant solar system. Prior to landing on a planet you measure its diameter to be 1.

Alja [10]

Answer:

Part a)

$M = 7.25 \times 10^{25} kg$

Part b)

$M = 2\times 10^{30} kg$

Explanation:

Part a)

As we know that the diameter of the planet is given as

$d = 1.8 \times 10^7 m$

now the radius of the planet is given as

$r = 9 \times 10^6 m$

now we know that the acceleration due to gravity of the planet is given by the equation

$g = \frac{GM}{r^2}$

here we know that

$g = 59.7 m/s^2$

now from above equation we have

$59.7 = \frac{(6.67 \times 10^{-11})M}{(9\times 10^6)^2}$

now we have

$M = 7.25 \times 10^{25} kg$

Part b)

Now by kepler's law we know that

time period of revolution of planet about the star is given as

$T = 2\pi \sqrt{\frac{r^3}{GM}}$

so we have

$\frac{T_1^2}{T_2^2} = \frac{r_1^3}{r_2^3}$

now we have

$\frac{1^2}{402^2} = \frac{(1.5 \times 10^11)^3}{r^3}}$

$rr = 8.17 \times 10^{12} m$

mula of time period

$402\times (365\times 24 \times 3600) = 2\pi \sqrt{\frac{(8.17\times 10^12)^3}{(6.67\times 10^{-11})M}}$

Now we have

$M = 2\times 10^{30} kg$

7 0

3 years ago

“Do you think that the role of culture, gender,

Serjik [45]

Answer:

this is based on your opinion but mine is...

Explanation:

Do you think that the role of culture, gender, and/or race has changed in sclence between the times we are learning about and today's times? If so, how? If not, explain your thoughts?

Yes by how because Race’ cannot be biologically defined due to genetic variation among human individuals and populations. (A) The old concept of the “five races:” African, Asian, European, Native American, and Oceanian. According to this view, variation between the races is large, and thus, the each race is a separate category. Additionally, individual races are thought to have a relatively uniform genetic identity. (B) Actual genetic variation in humans. Human populations do roughly cluster into geographical regions. However, variation between different regions is small, thus blurring the lines between populations. Furthermore, variation within a single region is large, and there is no uniform identity.

3 0

3 years ago

Students create a standing wave with three loops on a slinky 3.75 m longThey time 20 oscillations in 6.73 . What frequency would

yaroslaw [1]

Answer:

$f = 4.95\ hz$

Explanation:

Given,

Student create wave of three loop on a slinky 3.75 m.

number of oscillations= 20

Time, t = 6.73 s

Frequency = $\dfrac{20}{6.73}$

= 2.97 Hz

We need to find frequency when 5 loops is created.

$f = \dfrac{5}{3} \times 2.97$

$f = 4.95\ hz$

5 0

3 years ago

What is the current in milliamperes produced by the solar cells of a pocket calculator through which 4.2 C of charge passes in 2

Leni [432]

Answer:

Explanation:

Current produced by the solar cells of the pocket calculator is expressed using the formula I = Q/t where;

Q is the charge (in Columbs)

t is the time (in seconds)

Given parameters

Q = 4.2C

t = 2.7 hrs

t = 2.7*60*60

t = 9720 seconds

Required

Current produced by the solar cell I

Substituting the given values into the formula;

I = 4.2/9720

I = 0.000432A

I = 0.432mA

Hence, the current in milliamperes produced by the solar cells of a pocket calculator is 0.432mA

5 0

3 years ago