An iron of length `50cm` is joined at an end to copper rod to length `100cm` at `20^(0)C.` Find the length of the system at `100^(0)C` and average coefficient of linear expansion of the systeam.
`(*_(iron) = 12 xx 10^(-6 //0)C and*_(copper) = 17 xx 10^(-6 //0)C.)`

Explanation

To solve the problem, we will follow these steps:

### Step 1: Understand the problem
We have two rods: an iron rod of length 50 cm and a copper rod of length 100 cm, both at an initial temperature of 20°C. We need to find the total length of the system at a final temperature of 100°C and the average coefficient of linear expansion of the system.

### Step 2: Identify the given data
- Length of iron rod, \( L_1 = 50 \, \text{cm} \)
- Length of copper rod, \( L_2 = 100 \, \text{cm} \)
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