Chapter 8 Modelling In Mecanics

Question 1

Gravity def

Answer 1

The force of attraction to the Earth, measured at 9.8 ms-2. It is uniform and acts vertically downwards

Question 2

Air resistance def?

Answer 2

The friction an object experiences as it moves through space

Question 3

Wire def

Answer 3

A rigid, thin length of metal, treated as one dimensional, either smooth or rough

Question 4

Rough def

Answer 4

This takes into account friction on surfaces

Question 5

Smooth def

Answer 5

Assumes there is no friction between the surface and the object

Question 6

Inextensible def

Answer 6

Does not stretch under a load. Acceleration is constant in objects connected by a taut Inextensible string

Question 7

Light def

Answer 7

Its mass is very small(regarded as 0) such as a string or a pulley. Tension is the same at both end of the light string

Question 8

Lamina?

Answer 8

An object with two dimensions (length and width) such as a sheet of metal. It is evenly distributed across a flat surface

Question 9

Rod def

Answer 9

An object with one dimension (length) such as a pole and a beam. It’s mass is distributed along a straight line. It is rigid (does not bend or buckle)

Question 10

Particle def?

Answer 10

Dimensions of the object are negligible, it’s mass is concentrated at a single point. Air resistance and rational forces can be ignored