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3 years ago

6

Explain why the atomic mass of an element is a weighted-average mass

1 answer:

Sliva [168]3 years ago

3 0

The isotopes contribute to the average atomic mass based on their abundance. The result is that the "average" mass for the atoms of an element is dictated by the most abundant or common isotope. The average atomic mass for carbon is 12.0107 amu. The atomic mass as displayed on the periodic table is a weighted average relative atomic mass of the naturally occuring isotopes of that element. An isotope is an element with the same number of protons but a different number of neutrons For example - Carbon naturally occurs in isotopes C12, C13 and C14 with abundances of 98.9% 1.1% and 'trace' respectively. the average mass is then calculated by 12*98.9%+13*1.1% = 12.01g/mol

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A mass is placed at the end of a spring. It has starting velocity of V & allowed to oscillate freely. If the mass has a star

LiRa [457]

Answer:

Equation for SHM can be written

V = w A cos w t where w is the angular frequency and the velocity is a maximum at t = 0

V1 = w1 A cos w1 t

V2 = w2 A cos w2 t

V2 / V1 = w2 / w1 since cos X t = 1 if t = zero

V2 / V1 = 2 pi f2 / (2 pi f1) = f2 / f1 = T1 / T2

If the velocity is twice as large the period will be 1/2 long

8 0

3 years ago

22) A driver traveling at 80 km/h brakes her 2000 kg truck to stop for a red light. How much internal energy is produced

blsea [12.9K]

Answer:

$E=4.9\times 10^5\ J$

Explanation:

Given that,

The speed of a driver, v = 80 km/h = 22.22 m/s

The mass of the truck, m = 2000 kg

We need to find how much internal energy is produced. The internal energy produced by a truck is its kinetic energy and it is given by :

$E=\dfrac{1}{2}mv^2\\\\E=\dfrac{1}{2}\cdot22.22^{2}\cdot2000\\\\E=493728.4\ J$

or

$E=4.9\times 10^5\ J$

So, $4.9\times 10^5\ J$ of internal energy is produced.

3 0

3 years ago

How was helium first discovered?

lora16 [44]

I think it’s the third one idk tho

3 0

3 years ago

Read 2 more answers

a 252,000j of heat energy is required to heat 2kg water. if (CH2O=42000j/kgk.what is change in temperature ?

navik [9.2K]

Answer:

theres an decrease in temperature because 252,000 is more than 42,000. so its colder and not as hot as 252,000.

Explanation:

4 0

2 years ago

two horses are pulling a 325 kg wagon, initially at rest. The horses exert 250 N and 178 N forward forces, respectively. Ignorin

Dovator [93]

Answer:

AFter 3.5 s, the wagon is moving at: $4.62\,\,\frac{m}{s}$

Explanation:

Let's start by finding first the net force on the wagon, and from there the wagon's acceleration (using Newton's 2nd Law):

Net force = 250 N + 178 N = 428 N

Therefore, the acceleration from Newton's 2nd Law is:

$F=m\,*\,a\\a = \frac{F}{m} \\a= \frac{428}{325}\, \frac{m}{s^2} \\a\approx 1.32 \,\,\frac{m}{s^2}$

So now we apply this acceleration to the kinematic expression for velocity in an object moving under constant acceleration:

$v_f=v_i+a\,*\,t\\v_f=0+1.32\,*\,3.5\,\,\frac{m}{s} \\v_f=4.62\,\,\frac{m}{s}$

7 0

3 years ago