Answer:
An element is a pure substance and is made of only one type of atom; it cannot be broken down into a simpler substance.
1.The answer is True
2.The answer is False
Answer:
D. 371 N
Explanation:
Friction force equals normal force times the coefficient of friction:
F = Nμ
Since the ground is level, normal force equals weight:
N = mg
Therefore:
F = mgμ
F = (61 kg) (9.8 m/s²) (0.62)
F = 371 N
Answer:
The capacitance of the capacitor is 
Explanation:
To solve this exercise it is necessary to apply the concepts related to Power and energy stored in a capacitor.
By definition we know that power is represented as

Where,
E= Energy
t = time
Solving to find the Energy we have,

Our values are:


Then,


With the energy found we can know calculate the Capacitance in a capacitor through the energy for capacitor equation, that is

Solving for C=



Therefore the capacitance of the capacitor is 
<span>If 1 eighth equals 1 billion 7 eighth equals 7 billion.
The asker of the second question needs a tutorial in radiometric dating. There is little likelihood that the daughter isotope has the same atomic weight as the parent isotope. To measure the mass isotopes doesn't tell us how many atoms of each exist. To get around that let's pretend — which will likely serve the purpose ineptly intended — that the values give an the particle ratio, 125:875.
The original parent isotope count was 125 + 875 = 1000. The remaining parent isotope is 125/1000 or 1/8. 1/8 = (1/2)^h, where h is the number of half-lives.
h = log (1/8) ÷ log(1/2) = 3
And 3 half-lives • 150,000 years/half-life = 450,000 years.</span>