Answer:

1. Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical DEVICE or machine system. The device trades off input forces against movement to obtain a desired amplification in the output force. The model for this is the law of the lever.

2.Intermolecular forces are the forces which mediate interaction between molecules, including forces of attraction or repulsion which act between atoms and other types of neighboring particles, e.g. atoms or ions

3.Kinetic friction, also known as dynamic friction or sliding friction, occurs when two objects are moving relative to each other and rub together (like a sled on the ground).

4.A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable PROPERTY of a magnet: a force that pulls on other ferromagnetic MATERIALS, such as iron, steel, nickel, cobalt, etc. and attracts or repels other magnets.

5.Area is the quantity that expresses the extent of a two-dimensional region, shape, or planar lamina, in the plane. Surface area is its analog on the two-dimensional surface of a three-dimensional object.

6.Rectilinear propagation of light refers to the propensity of light to travel along a straight line without any interference in its trajectory. When light travels through a medium, say air or water, it follows a straight line. However, the path only changes in CASE there is a shift in the medium.