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Flura [38]
3 years ago
9

Alexandra knows that the atomic number of the element potassium, K, is 19. She also knows that one particular isotope of potassi

um has a mass number of 39. How many neutrons can be found in the nucleus of this isotope of potassium?
A) 19

B) 20

C) 39

D) 58
Physics
1 answer:
fiasKO [112]3 years ago
8 0
I believe the answer is 58 but I’m not sure
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The expression below was formed by combining different gas laws.
kap26 [50]

Answer:

Avogadro's law.

Explanation:

Avogadro’s law states that, equal volumes of all gases at the same temperature and pressure contain the same number of molecules.

Mathematically,

V n

V = Kn where V = volume in cm3, dm3, ml or L; n = number of moles of gas;

K = mathematical constant.

The ideal gas equation is a combination of Boyle's law, Charles' law and Avogadro’s law.

V 1/P at constant temperature (Boyle’s law)

V T at constant pressure ( Charles’law)

V n at constant temperature and pressure ( Avogadro’s law )

Combining the equations yields,

V nT/P

Introducing a constant,

V = nRT/P

PV = nRT

Where P = pressure in atm, Pa, torr, mmHg or Nm-2; V = volume in cm3, dm3, ml or L; T = temperature in Kelvin; n = number of moles of gas in mol; R = molar gas constant = 0.082 dm3atmK-1mol-1

7 0
3 years ago
A 250 N force pulls on a box horizontally to the right. The box is moving at constant speed.
lana66690 [7]

Answer:

its 34

Explanation:

3 0
3 years ago
Find the force necessary to pull a 6 kg object 3 m/s2
mars1129 [50]

Answer:

<h2>18 N</h2>

Explanation:

The force acting on an object given it's mass and acceleration can be found by using the formula

force = mass × acceleration

From the question we have

force = 6 × 3

We have the final answer as

<h3>18 N</h3>

Hope this helps you

6 0
2 years ago
16x^2y^2-25a^2b^2<br>factorize the expression​
SIZIF [17.4K]

Answer:

(4xy+5ab)(4xy-5ab)

Explanation:

16x^{2}y^{2}-25a^{2}b^{2}

4^2 is 16 and 5^2 is 25,

Also, (x-a)(x+a) = x^2-a^2

So, this factorized is:

(4xy+5ab)(4xy-5ab)

Hope this helps!

8 0
3 years ago
A swimmer bounces straight up from a diving board and falls feet first into a pool. She starts with a velocity of 4.00 m/s, and
Svetlanka [38]

Answer:

a = 1.152s

b = 0.817 m

c = 7.29m/s

Explanation: let the following

From the first equation of linear motion

V = u+at..........1

parameters be represented as :

t = Time taken

v = Final velocity

a = Acceleration due to gravity = 9.8m/s²

u = Initial velocity = 4 m/s

s = Displacement

V = 0

Substitute the values into equation 1

0 = 4-9.8(t)

-4 = -9.8t

t = 4/9.8

t = 0.408s

From : s = ut+1/2at^2.........2

S = 4×0.408+0.5(-9.8)×0.408^2

S= 1.632-4.9(0.166)

S = 1.632-0.815

S = 0.817m

Her highest height above the board is 0.817 m

Total height she would fall is 0.817+1.90 = 2.717 m

From equation 2

s = ut+1/2at^2

2.717 m = 0t+0.5(9.8)t^2

2.717 m = 0+4.9t^2

2.717 m = 4.9t^2

2.717/4.9 = t^2

0.554 =t^2

t =√0.554

t = 0.744s

Hence, her feet were in the air for 0.744+0.408seconds

= 1.152s

Also recall from equation 1

V= u+at

V = 0+9.8(0.744)

V = 7.29m/s

Hence, the velocity when she hits the water is 7.29m/s

Finally,

a = 1.152s

b = 0.817 m

c = 7.29m/s

4 0
2 years ago
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