Canadian Forces Aptitude Test (CFAT) Practice

What is the volume of a cylinder expressed by the formula V = πr²h, if the volume is known to be 141.3 m³ and its height is 5 m? Calculate the radius.

1. 2 m

2. 3 m

3. 4 m

4. 5 m

The correct answer is: 3 m

To find the radius of the cylinder given the volume and height, we can start with the formula for the volume of a cylinder: \[ V = \pi r^2 h \] We know that the volume \( V \) is 141.3 m³ and the height \( h \) is 5 m. Plugging these values into the formula, we can solve for the radius \( r \). 1. Substitute the known values into the equation: \[ 141.3 = \pi r^2 \times 5 \] 2. Now, divide both sides by 5: \[ \frac{141.3}{5} = \pi r^2 \] \[ 28.26 = \pi r^2 \] 3. Next, solve for \( r^2 \) by dividing both sides by \( \pi \): \[ r^2 = \frac{28.26}{\pi} \] 4. Using the approximate value of \( \pi \) as 3.14, we calculate: \[ r^2 \approx \frac{28.26}{3.14} \approx 9 \] 5. Finally, take