<h2>
Answer: The half-life of beryllium-15 is 400 times greater than the half-life of beryllium-13.</h2>
Explanation:
The half-life 
of a radioactive isotope refers to its decay period, which is the average lifetime of an atom before it disintegrates.
In this case, we are given the half life of two elements:
beryllium-13: 
beryllium-15: 
As we can see, the half-life of beryllium-15 is greater than the half-life of beryllium-13, but how great?
We can find it out by the following expression:
Where 
is the amount we want to find:
Finally:
Therefore:
The half-life of beryllium-15 is <u>400 times greater than</u> the half-life of beryllium-13.
Answer
given,
heat added to the gas,Q = 3300 kcal
initial volume, V₁ = 13.7 m³
final volume, V₂ = 19.7 m³
atmospheric pressure, P = 1.013 x 10⁵ Pa
a) Work done by the gas
W = P Δ V
W = 1.013 x 10⁵ x (19.7 - 13.7)
W = 6.029 x 10⁵ J
b) internal energy of the gas = ?
now,
change in internal energy
Δ U = Q - W
Q = 3300 x 10³ cal
Q = 3300 x 10³ x 4.186 J
Q = 1.38 x 10⁷ J
now,
Δ U = 1.38 x 10⁷ - 6.029 x 10⁵
Δ U = 1.32 x 10⁷ J
Explanation:
Below is an attachment containing the solution.
Answer:
the velocity is 10 m/s
Explanation:
Using the expression for kinetic energy we have:
![Ek=\frac{1}{2} *m*v^{2} \\\\Ek=100J\\m=2kg\\v=\sqrt{(2*100/2)}\\ v=10[m/s]](https://tex.z-dn.net/?f=Ek%3D%5Cfrac%7B1%7D%7B2%7D%20%2Am%2Av%5E%7B2%7D%20%5C%5C%5C%5CEk%3D100J%5C%5Cm%3D2kg%5C%5Cv%3D%5Csqrt%7B%282%2A100%2F2%29%7D%5C%5C%20v%3D10%5Bm%2Fs%5D)
Answer:
Air at higher altitude is under less pressure than air at lower altitude because there is less weight of air above it, so it expands (and cools), while air at lower altitude is under more pressure so it contracts (and heats up).
Explanation:
Hope that helped
