What is the heating surface area of a tube with a diameter of 3 ½ inches and a length of 20 feet?

To calculate the heating surface area of a tube, the formula used is the surface area of a cylinder, which is given by the formula:

[ \text{Surface Area} = \pi \times d \times l ]

where ( d ) is the diameter of the tube and ( l ) is the length of the tube.

First, convert the diameter into feet:

• The diameter is 3.5 inches, which is converted to feet as follows:

[ 3.5 \text{ inches} \div 12 \text{ inches/foot} = 0.29167 \text{ feet} ]

Next, since the length is already in feet (20 feet), we can now plug the values into the surface area formula:

[ \text{Surface Area} = \pi \times (0.29167) \times (20) ]

Calculating this:

1. First, calculate ( \pi \times 0.29167 ):

[ \pi \times 0.29167 \approx 0.916 ]

2. Now, multiply this result by the length (20 feet):

[ 0.916 \times 20 \approx 18.32 \text{