Hello. These are practice questions from the internet. Can you please help me with them? The answers are already provided. I just need an explanation. Please provide an easy and clear explanation for the answers that a child can understand, and please don't use cursive as I can't read that.

19. A kite 100ft above the ground moves horizontally at a speed of 8 ft/s. At what rate is the angle between the string and the horizontal decreasing when 200 ft of string has been let out? Answer: 0.02 rad/s 20. A rectangular storage container with an open top is to have a volume of 10m. The length of its base is twice the width. Material for the base costs $10 per square meter. Material for the sides costs $6 per square meter. Find the cost of materials for the cheapest such container. Answer: $163.5412. Find the absolute minimum and absolute maximum values of f(x) = x + cot(x/2) on the interval (7/4, 71/4). Answer: Abs. Min. isf(/2) = w/2 + 1, Abs. Max. is f (37/2) = 37/2- 1