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.
The random variable in this experiment is a Continuous random variable.
Option D
<u>Explanation</u>:
The continuous random variable is random variable where the data can take infinite variables. For example random variable is taken for measuring "speed of automobiles" on the highways. The radar instrument depicts time taken by automobile in particular what speed. They are the generalization of discrete random variables not the real numbers as a random data is created. It gives infinite sets of all possible outcomes. It is obvious that outcomes of the instrument depend on some "physical variables" those are not predictable as depends on the situation.
Answer:
1) 50 seconds 2) 100°C
Explanation:
(Follows formula of Power=Energy/Time)
1) 500W x X = 2000J/kg°C x .25kg x 50°C
X = 50 seconds.
2) 2000W x 300s = 1000J/kg°C x 2kg x X
X = 300
Initial temperature => 400°C-300°C = 100°C
Would presume you are asked to find the volume, since there is no second volume.
By General Gas Law:
P₁V₁/T₁ = P₂V₂/T₂
1.6 * 168 /255 = 1.3*V₂/285
V₂ = 1.6 * 168 * 285 / (1.3*255)
V₂ = 231.095
Final volume ≈ 231 cm³
I am pretty sure the answer would be too stretch