A gymnast whose weight is 5 10 N hangs from the middle of a bar supported by two vertical strands of rope. What is the tension i
1 answer:
You might be interested in
Answer: (E) 300 bq
Explanation:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha, beta particles or gamma-radiations. The radioactive decay follows first order kinetics.
Half life is represented by
Half life of Thallium-208 = 3.053 min
Thus after 9 minutes , three half lives will be passed, after ist half life, the activity would be reduced to half of original i.e. , after second half life, the activity would be reduced to half of 1200 i.e.
, and after third half life, the activity would be reduced to half of 600 i.e.
,
Thus the activity 9 minutes later is 300 bq.
The freezing point depression of a solution containing 30.7 g of glycerin is calculated as -1.65°C
Equating :
It is given that,
Given mass of glycerin is = 30.7 grams (Solute)
Volume of water = 376 mL
or molar -freezing-depression point is = 1.86°C/m
Molar mass of glycerin = 92.09 g/mole
Now, to work out the value, the mass of water should be known. Thus, to calculate, the formula used will be:
Mass = Density X Volume
Mass = 1.0 g/mL X 376 mL
Mass = 376 g or 0.376 Kg
Using the formula of melting point depression, the equation becomes:
Δ = i ×
×m
T⁰- =
in which,
Δ = change in freezing point
Δ = freezing point of solution that has to be find
ΔT° = freezing point of water ()
Since, glycerin is a non-electrolyte, the Van't Hoff factor will be 1.
Substituting the values in the above equation:
0⁰C₋T = 1 ×1.86°C/m ×
= -1.65°C
Thus, the freezing point depression of a solution is -1.65°C
<h2 />Freezing point depression
Freezing point depression is a colligative property observed in solutions that results from the introduction of solute molecules to a solvent. The freezing points of solutions are all less than that of the pure solvent and is directly proportional to the molality of the solute
Is melting point elevation or depression?
Boiling point elevation is that the raising of a solvent's boiling point due to the addition of a solute. Similarly, melting point depression is the lowering of a solvent's freezing point due to the addition of a solute. In fact, because the boiling point of a solvent increases, its melting point decreases
Learn more about freezing point depression :
#SPJ4