How many stars are there in an Open Cluster?*

You can obtain a rough estimate of the size of a molecule by the following simple experiment. Let a droplet of oil spread out on

Marat540 [252]

Answer:

The diameter of the molecule of oil is $1.405 10 ^{-9} \ m$

Explanation:

We define density as

$\rho = \frac{mass}{volume}$

So, the volume for our oil will be

$volume = \frac{mass}{\rho}$

$volume = \frac{7.62 \ 10^{-7} \ kg}{ 912 \ \frac{kg}{m^3} }$

$volume = 8.355 \ 10 ^{-10} \ m^3$

the volume for a cylinder with radius r and height h is

$volume = \pi r^2 h$

So, we can obtain the height of the droplet of oil as:

$h = \frac{volume}{\pi r^2}$

the radius is

$r=43.5 \ cm = 0.435 \ m$

$h = 1.405 10 ^{-9} \ m^3$

And this is the diameter of the oil molecule.

6 0

3 years ago

How long does it take for a truck accelerating at 1.5 m/s^2 to got from rest to 75 km/hr

Free_Kalibri [48]

Answer:

t = 13.9s

Explanation:

u = 0 m/s

v = 75 km/h

= 20.83 m/s

a = 1.5 m/s²

Using

v = u + at

20.83 = 0 + 1.5t

t = 13.9s

6 0

3 years ago

The energy that generates wind comes from what source?

mamaluj [8]

The energy that generates wind on an individual basis originates with
one's habitual diet. On a world-wide basis, it comes from the sun.

6 0

2 years ago

Paul’s 10 kg baby sister Susan sits on a mat. Paul pulls the mat across the floor using a rope that is angled 30° above the floo

kiruha [24]

Answer:

The speed of Susan is 2.37 m/s

Explanation:

To visualize better this problem, we need to draw a free body diagram.

the work is defined as:

$W=F*d*cos(\theta)$

here we have the work done by Paul and the friction force, so:

$W_p=F_p*d*cos(0)\\F_p=30N*cos(30^o)=26N\\W_p=26*3*(1)=78J$

$W_f=F_f*d*cos(180)\\F_f=\µ*(10*9.8-30N*sin(30^o))=16.6N\\W_p=16.6*3*(-1)=50J$

Now the change of energy is:

$W_p-W_f=\frac{1}{2}m*v^2\\v=\sqrt{\frac{2(78J-50J)}{10kg}}\\v=2.37m/s$

4 0

3 years ago

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Which of the following best describes what went wrong with the scientists’ study? an improper experimental procedure the lack of

Rasek [7]

B- lack of control.

the scientists did not have a proper control group.

3 0

3 years ago

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