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3 years ago

A balloon filled with helium occupies 20.0 l at 1.50 atm and 25.0◦

1 answer:

5 0

At stp (standard temperature and pressure), the temperature is T=0 C=273 K and the pressure is p=1.00 atm. So we can use the ideal gas law to find the number of moles of helium:
$pV=nRT$
where p is the pressure (1.00 atm), V the volume (20.0 L), n the number of moles, T the temperature (273 K) and $R=0.082 atm L K^{-1} mol^{-1}$ the gas constant. Using the numbers and re-arranging the formula, we can calculate n:
$n= \frac{pV}{RT}= \frac{(1.00atm)(20.0L)}{(0.082 LatmK^{-1}mol^{-1})(273 K)}=0.89 mol$

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Help please. what is the formula BaF2 tells you about this element

nataly862011 [7]

Barium fluoride(BaF2) is a chemical compound of barium and fluorine and is a salt. It is a solid which can be a transparent crystal.

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3 years ago

A particle is moving in a circle of diameter 5. calculate the distance covered and the displacement when it completes 3 revoluti

Mamont248 [21]

Total distance covered is 47.1 m whereas displacement is zero.

<h3>Calculation:</h3>

Given,

Diameter, d = 5 m

No. of revolutions = 3

Radius, r = 5/2 = 2.5 m

To find,

Distance =?

Displacement =?

Distance covered in one revolution = 2πr

Put the values in this,

Distance = 2 × 3.14 × 2.5

= 15.7 m

Total distance covered in 3 revolution = 3 × 31.4

= 47.1 m

Displacement is the change in the position of the object or the distance between the initial and final position.

After 3 revolutions the particle comes back to its initial position. Therefore, the displacement is zero.

Hence, the total distance covered in 3 resolutions is 47.1 m whereas displacement is zero.

Learn more about distance and displacement here:

brainly.com/question/3243551

#SPJ4

5 0

1 year ago

Which property of water causes the cracks in the pavement in cold climates ?

amid [387]

“As temperatures drop, the pavement contracts, building up tensile stresses that lead to cracking,” states MnDOT's Research Services Section. “Fractures occur every 20 to 30 feet across the lane, allowing water to penetrate the structure, which further weakens the pavement layer and the base beneath

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3 years ago

Read 2 more answers

Four objects are situated along the y axis as follows: a 1.93-kg object is at +2.91 m, a 2.95-kg object is at +2.43 m, a 2.41-kg

Anna [14]

Answer:

0.958 m

Explanation:

So the total mass of the system is

M = 1.93 + 2.95 + 2.41 + 3.99 = 11.28 kg

let y be the distance from the center of mass to the origin. With the reference to the origin then we have the following equation

$My = m_1y_1 + m_2y_2 +m_3y_3 + m_4y_4$

$11.28y = 1.93*2.91 + 2.95*2.43 + 2.41*0 + 3.99*(-0.496) = 10.806$

$y = \frac{10.806}{11.28} = 0.958 m$

So the center of mass is 0.958 m from the origin

3 0

3 years ago

A 55.0-kg lead ball is dropped from the Leaning Tower of Pisa. The tower is 55.0 m high. What is the speed of the ball after it

PolarNik [594]

Answer:

The speed of the ball is 9.07 m/s.

Explanation:

Given that,

Mass of the lead ball, m = 55 kg

Height of the tower, h = 55 m

We need to find the speed of the ball it has traveled 4.20 m downward, x = 4.2 meters

The initial speed of the ball will be 0 as it was at rest initially. Let v is the speed of the ball after it has traveled 4.20 m downward. It is a case of equation of motion such that :

$v^2-u^2=2ax$

$v^2=2ax$

Here, a = g

$v^2=2\times 9.8\times 4.2$

v = 9.07 m/s

So, the speed of the ball is 9.07 m/s. Therefore, this is the required solution of given condition.

4 0

3 years ago