What is the dimension of coefficient of friction?

What is the dimension of in_o ?

To set a body mass 5 kg in motion over a horizontal surface a minimum force of 30 N has to be applied. What is the value of the coefficient of friction?

A ball of 15 kg is kept-at a horizontal surface. To make it move at least 30 N force is to be acted upon that body. What is the value of the coefficient of friction?

The dimension of coefficient of viscosity-

The dimension of coefficient of viscocity is

The dimension of the coefficient of viscosity is