The ratio between the force of sliding friction and the normal force of an object is called a. rolling friction b. the drag c. the coefficient of friction d. the starting friction

The correct answer is C.

Explanation: Frictional force is the contact force which resists the motion of one surface on another.

Mathematically,

where,

f = frictional force

= Coefficient of friction

N = normal force acting on a body

We need to find the ratio of force of sliding friction ( which is a type of frictional force) and the normal force acting on an object. This will be equal to coefficient of friction.

i think it is d. e because the next one is igneous.

vanderwaal's forces of attraction are the electrostatic intermolecular forces that exist in a molecule due to the temporary or permanent dipoles that are developed in a molecule. in , the major intermolecular forces are dipole-dipole interactions as the molecule is polar (bent structure). so the vanderwaal's forces of interaction in between molecules are the permanent dipole-dipole interactions that develop due to the dipole that exists in between the polar h - s bond. the positively charged hydrogen atom is attracted towards the negative end of the dipole that is sulfur of the adjacent molecule. therefore, these forces of attraction are relatively stronger than that of london dispersion forces that exist in non polar molecules.