Please look a picture.

I think the book made a mistake.

The answer should be 89.9N/m.

Why? Because they calculated the linear density μ wrongly. They should have done $$\frac{75*10^{-3}kg}{1.8m}$$

I think the book made a mistake.

The answer should be 89.9N/m.

Why? Because they calculated the linear density μ wrongly. They should have done $$\frac{75*10^{-3}kg}{1.8m}$$

http://ift.tt/1hRWbJm