Radioactive decay is given by:
N = No x e^(-λt)
We know that N/No has to be 0.05
λ = 0.15
0.05 = e^(-0.15t)
t = ln(0.05)/(-0.15)
t = 19.97 days
Answer:
0.25 m
Explanation:
We can solve the problem by using the lens equation:
where
f is the focal length
p is the distance of the object from the lens
q is the distance of the image from the lens
In this problem, we have
f = +20 cm=+0.20 m (the focal length is positive for a converging lens)
q = +1.0 m (the image distance is positive for a real image)
Solving the equation for p, we find
Answer:
(i) false
(ii) true
(iii) true
(iv) false
Explanation:
(i) The ratio of Cp and Cv is not constant for all the gases. It is because the value of cp and Cv is different for monoatomic, diatomic and polyatomic gases.
So, this is false.
(ii) For monoatomic gas
Cp = 5R/2, Cv = 3R/2
So, thier ratio
Cp / Cv = 5 / 3 = 1.67
This statement is true.
(iii) for diatomic gases
Cp = 7R/2, Cv = 5R/2
Cp / Cv = 7 / 5 = 1.4
This statement is true.
(iv) It is false.
Answer:
B, C and E
Explanation:
The unit of resistance in the international system is the Ohm, the equation that describes the resistance is:
Where (l) is for lenght of the wire, (S) is the area and (p) its the constant associated to the conductor.
It's related by the Ohm's Law: