Question

question 3
3.1 a builder is completing 75 low - cost houses to reduce the water bill, each house will have a rain water tank. the tank will be placed on a cubic concrete stand as shown below.
the tank has a height of 2 200mm
the volume of a tank is 5 000l
use the above information to answer the questions that follow.
3.1.1 explain the difference between a diameter and a radius.
3.1.2 if the diameter of the tank is 1.7 meter. calculate the capacity of the tank if it is 75% full.
you may use the following formula:
capacity = π×r²×height, where π = 3.142
3.1.3 calculate the circumference of the tank in centimeters.
you may use the formula
circumference of the tank = π×diameter.

Explanation:

Step1: Define diameter and radius

The radius ($r$) of a circle is the distance from the center of the circle to any point on its circumference. The diameter ($d$) is a straight - line segment that passes through the center of the circle and has its endpoints on the circumference. The relationship between them is $d = 2r$.

Step2: Calculate capacity when 75% full

First, find the radius from the diameter. Given $d=1.7$ meters, then $r=\frac{d}{2}=\frac{1.7}{2}=0.85$ meters. The height $h = 2200$ mm $= 2.2$ meters. Using the formula $V=\pi r^{2}h$ with $\pi = 3.142$, we have $V = 3.142\times(0.85)^{2}\times2.2=3.142\times0.7225\times2.2 = 5.003993$ cubic meters. Since $1$ cubic meter $ = 1000$ liters, the full - capacity of the tank is $5003.993$ liters. When it is 75% full, the capacity is $0.75\times5003.993 = 3752.99475\approx3753$ liters.

Step3: Calculate circumference in centimeters

Given $d = 1.7$ meters $=170$ centimeters. Using the formula $C=\pi d$ with $\pi = 3.142$, we get $C=3.142\times170 = 534.14$ centimeters.

Answer:

3.1.1: The radius is the distance from the center of a circle to its circumference, and the diameter is a line segment through the center with endpoints on the circumference, and $d = 2r$.
3.1.2: Approximately 3753 liters.
3.1.3: 534.14 centimeters.