Question

Which of the following would increase friction?

A. Sand
B. Motor oil
C. Water
D. Soap

Answer 1

Sand since it's more solid. Liquid would not increase fiction.

Answer 2

A. Sand

Step-by-step explanation:

Friction increases with the roughness of the surface.

Motor oil, water and soap will coat the surface in contact and will reduce the roughness of the surface. So the friction will not increase

Whereas, sand will increase the surface roughness by scratching the surface. This in turn will increase the friction