B. An apple about to fall from a tree branch
This is because potential energy is the energy before its actuall motion, or before kinetic energy (energy in motion). And the apple ABOUT TO FALL mentions a gravitational example.
Answer:
1 day
Explanation:
Let the safe level = x
The current level = x + 0.2x = 1.2 x
Thus,
Half life = 3.8 days
Where, k is rate constant
So,
The rate constant, k = 0.1824 days⁻¹
Using integrated rate law for first order kinetics as:
![[A_t]=[A_0]e^{-kt}](https://tex.z-dn.net/?f=%5BA_t%5D%3D%5BA_0%5De%5E%7B-kt%7D)
Where,
![[A_t]](https://tex.z-dn.net/?f=%5BA_t%5D)
is the concentration at time t
![[A_0]](https://tex.z-dn.net/?f=%5BA_0%5D)
is the initial concentration
So,
![\frac {[A_t]}{[A_0]}](https://tex.z-dn.net/?f=%5Cfrac%20%7B%5BA_t%5D%7D%7B%5BA_0%5D%7D)
= x / 1.2 x = 0.8333
t = ?
![\frac {[A_t]}{[A_0]}=e^{-k\times t}](https://tex.z-dn.net/?f=%5Cfrac%20%7B%5BA_t%5D%7D%7B%5BA_0%5D%7D%3De%5E%7B-k%5Ctimes%20t%7D)
t ≅ 1 day
<u>Lab must be vacated in 1 day.</u>
Below the crust is the mantle, a dense, hot layer of semi-solid rock approximately 2,900 km thick. The mantle, which contains more iron, magnesium, and calcium than the crust, is hotter and denser because temperature and pressure inside the Earth increase with depth.
Hope this helped! :)
Can I be brainliest please?
the middle part in the center of the diagram. the nucleus is always in the center.
