To solve this, we need to approach it step by step:

Step 1: Determine the Required Size of the Steel Beam

1. Length of the Beam: The beam is 60 feet long.

2. Load on the Beam: We need to calculate the load the beam must support. Since it's for one storey of a house that is 30 feet wide, we will need information on the load per foot of beam.

   • The load on the beam depends on several factors like the total weight of the house, the type of construction, and the weight distribution.
   • For now, assuming an average load of 1.5 kN per foot (this is an estimate based on typical loads in residential buildings), the total load on the beam is:

   $\text{Total Load} = 60 \, \text{ft} \times 1.5 \, \text{kN/ft} = 90 \, \text{kN}$

   You can adjust this figure based on the actual specifications of your structure.

3. Moment of Inertia: The size of the steel beam depends on the bending moment the beam will experience, which depends on the load. A common choice for such beams is a wide flange steel beam (W-beam), where the number format is W $\text{xx} \times \text{yy}$, indicating the beam’s weight per unit length and depth.

   Without detailed calculations of the bending moment, we can select a beam with sufficient strength for the estimated load. For a typical 1-storey residential house, a W8x24 beam is often used for a 60-foot span under moderate loads.

Step 2: Calculate the Weight of the Steel Beam

1. Weight of the Beam: The weight of the beam can be calculated based on its size. For example, a W8x24 beam weighs approximately 24 pounds per foot. To convert pounds to kilograms:

   $1 \, \text{lb} = 0.453592 \, \text{kg}$

   So for a W8x24 beam, the weight is:

   $\text{Weight per foot} = 24 \, \text{lb/ft} \times 0.453592 = 10.89 \, \text{kg/ft}$

2. Total Weight of the Beam: The total weight of the 60-foot long beam is:

   $\text{Total Weight} = 60 \, \text{ft} \times 10.89 \, \text{kg/ft} = 653.4 \, \text{kg}$

Final Answers:

1. Size of Steel Beam: W8x24
2. Weight of the Beam: 653.4 kg

Let me know if you need more details or have any questions!

Additional Questions:

1. What are the different types of steel beams used in construction?
2. How does the span of a beam affect its required size?
3. How do you calculate the maximum bending moment for a steel beam?
4. What is the significance of the beam's weight per unit length (e.g., W8x24)?
5. What factors should be considered when choosing the steel grade for a beam?

Tip:

When selecting a beam, always ensure that the beam is designed to withstand both the dead load (permanent load like the weight of the house) and live load (temporary loads like furniture or people).