Answer:
During stage 3 - late expanding (of demogrpahic transition model)
Explanation:
During stage 3, birth rate begins to decline as infant mortality is lower and women have more access to education, family planning, and contraceptives. Children are not needed as "free labor" as they might have been in earlier stages.
Answer:
2.47 m
Explanation:
Let's calculate first the time it takes for the ball to cover the horizontal distance that separates the starting point from the crossbar of d = 52 m.
The horizontal velocity of the ball is constant:

and the time taken to cover the horizontal distance d is

So this is the time the ball takes to reach the horizontal position of the crossbar.
The vertical position of the ball at time t is given by

where
is the initial vertical velocity
g = 9.8 m/s^2 is the acceleration of gravity
And substituting t = 2.56 s, we find the vertical position of the ball when it is above the crossbar:

The height of the crossbar is h = 3.05 m, so the ball passes

above the crossbar.
Answer:
≈ 2.1 R
Explanation:
The moment of inertia of the bodies can be calculated by the equation
I = ∫ r² dm
For bodies with symmetry this tabulated, the moment of inertia of the center of mass
Sphere
= 2/5 M R²
Spherical shell
= 2/3 M R²
The parallel axes theorem allows us to calculate the moment of inertia with respect to different axes, without knowing the moment of inertia of the center of mass
I =
+ M D²
Where M is the mass of the body and D is the distance from the center of mass to the axis of rotation
Let's start with the spherical shell, axis is along a diameter
D = 2R
Ic =
+ M D²
Ic = 2/3 MR² + M (2R)²
Ic = M R² (2/3 + 4)
Ic = 14/3 M R²
The sphere
Is =
+ M [
²
Is = Ic
2/5 MR² + M
² = 14/3 MR²
² = R² (14/3 - 2/5)
= √ (R² (64/15)
= 2,066 R