# Question #bc8d3

##### 1 Answer

Approximately 4.6 Kg/m to 2 decimal ,places

Exactly

#### Explanation:

The shortcut method is based on what follows:

I will highlight in red the bit that the shortcut method uses.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Using ratios in fractional format.

Lookin at the units to decide how we write this. We are told

'mass per metre' so this is written as:

The word 'per' means for each of 1. So 'per metre' is for each of 1 metre

Thus we need to change the

Note that

So we multiply top and bottom of

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

To determine the mass for one metre apply

Now you see where the shortcut approach comes from

This produces a decimal solution which I am choosing to be rounded, so not precise.

Or you can write: