C. Composition
is the answer
Answer:
Model
Explanation:
A model of anything is something you make to represent it in it's physical world form
No, work is not done whenever you hold a heavy object for a long time
<h3>What is work done ?</h3>
The result of a force's displacement and its component of force exerted by the object in the direction of displacement is what is known as the force's work. When we push a block with some force, the body moves quickly and work is completed.
- No work, as that term is used here, is done until the object is moved in some way and a component of the force travels along the path that the object is moved. Because there is no displacement when holding a heavy object still, energy is not transferred to it.
Learn more about Work done here:
brainly.com/question/25573309
#SPJ4
Answer:
Iron remains = 17.49 mg
Explanation:
Half life of iron -55 = 2.737 years (Source)
Where, k is rate constant
So,
The rate constant, k = 0.2533 year⁻¹
Time = 2.41 years
![[A_0]](https://tex.z-dn.net/?f=%5BA_0%5D)
= 32.2 mg
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
is the initial concentration
So,
![[A_t]=32.2\times e^{-0.2533\times 2.41}\ mg](https://tex.z-dn.net/?f=%5BA_t%5D%3D32.2%5Ctimes%20e%5E%7B-0.2533%5Ctimes%202.41%7D%5C%20mg)
![[A_t]=32.2\times e^{-0.610453}\ mg](https://tex.z-dn.net/?f=%5BA_t%5D%3D32.2%5Ctimes%20e%5E%7B-0.610453%7D%5C%20mg)
![[A_t]=17.49\ mg](https://tex.z-dn.net/?f=%5BA_t%5D%3D17.49%5C%20mg)
<u>Iron remains = 17.49 mg</u>
