The answer should be 2 13/30.
Answer:

Step-by-step explanation:
Suppose at t = 0 the person is 1m above the ground and going up
Knowing that the wheel completes 1 revolution every 20s and 1 revolution = 2π rad in angle, we can calculate the angular speed
2π / 20 = 0.1π rad/s
The height above ground would be the sum of the vertical distance from the ground to the bottom of the wheel and the vertical distance from the bottom of the wheel to the person, which is the wheel radius subtracted by the vertical distance of the person to the center of the wheel.
(1)
where
is vertical distance from the ground to the bottom of the wheel,
is the vertical distance from the bottom of the wheel to the person, R = 10 is the wheel radius,
is the vertical distance of the person to the center of the wheel.
So solve for
in term of t, we just need to find the cosine of angle θ it has swept after time t and multiply it with R

Note that
is negative when angle θ gets between π/2 (90 degrees) and 3π/2 (270 degrees) but that is expected since it would mean adding the vertical distance to the wheel radius.
Therefore, if we plug this into equation (1) then

4. because it is reduced and the simplest to understand
The ladder, the wall and the floor form together a triangle rectangle, where the ladder is the hypotenuse of the triangle and the floor and wall are the cathetus. We know from Pythagoreas theorem that the square of the hypotenuse is equal to the sum of the two cathetus squared added, so we can write an equation with the data we have:
hyp^2 = cath1^2 + cath2^2
<span>hyp^2 = wall^2 + floor^2
</span>so we have the hypotenuse value, the floor value and the unknown is the wall height:
(22)^2 = wall^2 + (7)^2
484 = wall^2 + 49
wall^2 = 484 - 49 = 435
wall = √435
wall = 20.9
therefore the ladder touches the wall 20.9 feet above the ground
It is very important to read the question very minutely and then it would be easy to reach a logically correct solution. It is important to note that "y" is greater than or equal to 12 and y is considered as all real numbers. Then we can mathematically represent this situation as
y <span>≥ 12</span>