7. All of the following descriptions are true about descriptive method of research except one:

a 100g ice cube at 0 degrees celsius is placed in 650 grams of water at 25 degrees celsius. When the mixture reaches equillibriu

Artyom0805 [142]

Answer:

The latent heat of fusion of water is 334.88 Joules per gram of water.

Explanation:

Let the latent heat of ice be 'x' J/g

1) Thus heat absorbed by 100 gram of ice to get converted into water equals

$Q_1=100\times x$

2) heat energy required to raise the temperature of water from 0 to 25 degree Celsius equals

$Q_2=100\times 4.186\times 11=4604.6Joules$

Thus total energy needed equals $Q_1+Q_2=100x+4604.6$

3) Heat energy released by the decrease in the temperature of water from 25 to 11 degree Celsius is

$Q_3=650\times 4.186\times (25-11)\\\\Q_{3}=38092.6Joules$

Now by conservation of energy we have

$Q_1+Q_2=Q_3\\\\100x+4604.6=38092.6\\\\\therefore x=\frac{38092.6-4604.6}{100}=334.88J/g$

6 0

3 years ago

You use 8x binoculars were used on a warbler (14cm long) in a tree 18cm away. What angle (in degrees) does the image of the warb

mafiozo [28]

Answer:

The angle it subtend on the retina is $\theta_z = 0.44586^o$

Explanation:

From the question we are told that

The length of the warbler is $L = 14cm = \frac{14}{100} = 0.14m$

The distance from the binoculars is $d = 18cm = \frac{18}{100} = 0.18m$

The magnification of the binoculars is $M =8$

Without the 8 X binoculars the angle made with the angular size of the object is mathematically represented as

$\theta = \frac{L}{d}$

$\theta = \frac{0.14}{0.18}$

$= 0.007778 rad$

Now magnification can be represented mathematically as

$M = \frac{\theta _z}{\theta}$

Where $\theta_z$ is the angle the image of the warbler subtend on your retina when the binoculars i.e the binoculars zoom.

So

$\theta_z = M * \theta$

=> $\theta_z =8 * 0.007778$

$= 0.0622222224$

Generally the conversion to degrees can be mathematically evaluated as

$\theta_z = 0.062222224 * (\frac{360 }{2 \pi rad} )$

$\theta_z = 0.44586^o$

7 0

3 years ago

How expensive is genetic counseling and reproductive technology?

ExtremeBDS [4]

Answer:

Genetic counseling without testing cost on average $213, whereas counseling, testing, and disclosure of results totaled $2057. A brief physician-based counseling instead of genetic counselor-based counseling would produce only small reductions in total costs.

hope it helps, please give me brainliest.

8 0

2 years ago

A bullet is fired through a wooden board with a thickness of 9.0 cm. The bullet hits the board perpendicular to it, and with a s

gtnhenbr [62]

Answer:

-387883.3 m/s²

0.000286168546055 seconds

Explanation:

t = Time taken

u = Initial velocity = 370 m/s

v = Final velocity = 259 m/s

s = Displacement = 9 cm

a = Acceleration

$v^2-u^2=2as\\\Rightarrow a=\dfrac{v^2-u^2}{2s}\\\Rightarrow a=\dfrac{259^2-370^2}{2\times 9\times 10^{-2}}\\\Rightarrow a=-387883.3\ m/s^2$

The acceleration of the bullet is -387883.3 m/s²

$v=u+at\\\Rightarrow t=\dfrac{v-u}{a}\\\Rightarrow t=\dfrac{259-370}{-387883.3}\\\Rightarrow t=0.000286168546055\ s$

The time taken is 0.000286168546055 seconds

4 0

3 years ago

Which type of disease cannot be spread from one person to another

aniked [119]

I believe that would be D.

Cardiovascular disease generally refers to conditions that involve narrowed or blocked blood vessels that can lead to a heart attack, chest pain, or stroke. Which it has nothing to do with being infectious.

7 0

2 years ago