Propose a situation where friction is undesirable.

Trying to move a large object such as a furniture piece across carpet.

Kinetic energy = 1/2mv^2. since the mass is constant we can form a ratio of it's kinetic energy at 60 divided by that at 30 to see ke(60)/ke(30) = +(60^2)/30^2). this may be said to 300% increase.

A. they hold atoms  together with a molecule.its a force that exist between molecules. hope this .