Answer with Explanation:
We are given Avogadro's constant =
There are eight significant figures.
We have to round off.
1.If we round off to four significant figures
The ten thousandth place of Avogadro's constant is less than five therefore, digits on left side of ten thousandth place remains same and digits on right side of ten thousandth place and ten thousandth place replace by zero.
Then ,Avogadro's constant can be written as

If we round off to 2 significant figures
Hundredth place of given number is less than 5 therefore, digits on left side of hundredth place remains same and digits on right side of hundredth place and hundredth place replace by zero.
Then,Avogadro's constant can be written as

If we round off six significant figures
6 is greater than 5 therefore, 1 will be added to 3 and digits on right side of 6 and 6 replace by zero and digits on left side of 6 remains same except 3.
Then, the Avogadro's constant can be written as

Answer:
The wife have to sit at 0.46 L from the middle point of the seesaw.
Explanation:
We need to make a sketch of the seesaw and the loads acting over it.
And by the studying of the Newton's law we can find the equation useful to find the distance of the mother sitting on the seesaw with respect to the center ot the pivot point.
A logical intuition will give us the idea that the mother will be on the side of her son to make the balance.
The maximum momentum with respect to the pivot point (0) will be:

Where L/2 is the half of the distance of the seesaw
Therefore the other loads ( mom + son) must be create a momentum equal to the maximum momentum.
Answer:
Half life of S = 3.76secs
Explanation:
The concept of half life in radioactivity is applied. Half life is the time taken for a radioactive material to decay to half of its initial size.
For part 1 - How much signal will be degraded in 1secs = 1/3.9 = 0.2564
for part 2 - How much signal will be degraded in 1secs = 1/104 = 0.009615
Simply say = 1/3.9 + 1/104 = 0.266015
So both part 1 and part 2 took 1/0.266015 = 3.76secs is the half life of S when both pathways are active
Answer:
The other angle is 30 degrees.
Explanation:
The range of projectile is given by :

Here,
u is the speed of launch of projectile
Here, 
We need to find the other launch angle when the projectile have the same range, such that,




So, the other angle is 30 degrees. Hence, this is the required solution.
Answer:
ω = √(2T / (mL))
Explanation:
(a) Draw a free body diagram of the mass. There are two tension forces, one pulling down and left, the other pulling down and right.
The x-components of the tension forces cancel each other out, so the net force is in the y direction:
∑F = -2T sin θ, where θ is the angle from the horizontal.
For small angles, sin θ ≈ tan θ.
∑F = -2T tan θ
∑F = -2T (Δy / L)
(b) For a spring, the restoring force is F = -kx, and the frequency is ω = √(k/m). (This is derived by solving a second order differential equation.)
In this case, k = 2T/L, so the frequency is:
ω = √((2T/L) / m)
ω = √(2T / (mL))