<h2>For Second Solid Lumped System is Applicabe</h2>
Explanation:
Considering heat transfer between two identical hot solid bodies and their environments -
- If the first solid is dropped in a large container filled with water, while the second one is allowed to cool naturally in the air than for second solid, the lumped system analysis more likely to be applicable
- The reason is that a lumped system analysis is more likely to be applicable in the air than in water as the convection heat transfer coefficient so that the Biot number is less than or equal to 0.1 that is much smaller in air
Biot number = the ratio of conduction resistance within the body to convection resistance at the surface of the body
∴ For a lumped system analysis Biot number should be less than 0.1
Answer: There will be 75258 nuclei left at 6 pm.
Explanation:
a) half-life of the radioactive substance:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
b) Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = time for decomposition = 6 hours ( from 12 noon to 6 pm)
A = activity at time t = ?
= initial activity = 600, 000
Thus there will be 75258 nuclei left at 6 pm.
Effect of temperature.
"If the temperature of the substance is increased then the rate of chemical reaction is also increased because the kinetic energy is greater."
Effect of surface area.
"If the surface area is increased then the rate of reaction is increased because there will be more active sites for the reaction to occur.
Answer: A.
series or parallel
Explanation:
Total resistance across any branch of a circuit can be found by analyzing whether the branch is connected in series or parallel.
The resistors are connected either in series or parallel. Therefore, the resistance of resistors across a circle can be calculated in series and parallel.
