Lots of reasons. one reason i lie alot (a very bad habit) is im scared of what will happen if i tell the truth. the truth is always better, though.
Answer:
c) 2.02 x 10^16 nuclei
Explanation:
The isotope decay of an atom follows the equation:
ln[A] = -kt + ln[A]₀
<em>Where [A] is the amount of the isotope after time t, k is decay constant, [A]₀ is the initial amount of the isotope</em>
[A] = Our incognite
k is constant decay:
k = ln 2 / Half-life
k = ln 2 / 4.96 x 10^3 s
k = 1.40x10⁻⁴s⁻¹
t is time = 1.98 x 10^4 s
[A]₀ = 3.21 x 10^17 nuclei
ln[A] = -1.40x10⁻⁴s⁻¹*1.98 x 10^4 s + ln[3.21 x 10^17 nuclei]
ln[A] = 37.538
[A] = 2.01x10¹⁶ nuclei remain ≈
<h3>c) 2.02 x 10^16 nuclei</h3>
Explanation :
A circuit is the representation of the path of the flow of current. The circuit can be either closed or open.
When the switch is off the circuit is closed circuit and when the switch is not connected the circuit is open.
The items that are sufficient to make a circuit are as follows :
- Voltage source like a battery.
- Resistors or electrical equipment like heater, motor etc.
Other components can be ammeter, voltmeter, ac source, variable resistors etc.
Answer: The cylinder
Explanation:
Among all other solid shapes, the sphere has the smallest area for a given volume.
By experiment, the ratio of the radius of a sphere to a cylinder of equal volume is less than 1.
Recall;
That the Rate of transfer of convective heat (Q) = h × A ×change in temperature.
Where ,
h= the co efficient of convective heat transfer
A= the cross sectional area.
As such, since the sphere has a smaller surface area relative to the cylinder, the sphere transfers heat slower than the cylinder.
Therefore, if the sphere and cylinder are exposed to convection in the same environment, then, the cylinder cools faster.
PS; the more the Area, the higher the rate of heat transfer and vice versa.
