Chapter 8 stats 1

Question 1

Particle

Answer 1

• no dimensions, rotational forces or air resistance

- mass concentrated at a single point

Question 2

Rod

Answer 2

• all dimensions but one are negligible (no thickness)
• rigid
• mass is concentrated along a line

Question 3

Lamina

Answer 3

• has area

- mass is distributed across a flat surface

Question 4

Uniform body

Answer 4

• mass is concentrated at centre of mass

Question 5

Light object

Answer 5

• zero mass

- tension is the same at both ends

Question 6

Inextensible string

Answer 6

• acceleration is the same

Question 7

Smooth surface

Answer 7

• no friction

Question 8

Rough surface

Answer 8

• there is friction

Question 9

Wire

Answer 9

• treated as one dimensional

Question 10

Smooth and light pulley

Answer 10

• pulley has no mass

- tension is the same on either side of the pulley

Question 11

Bead

Answer 11

• moves freely along wire/string

- tension is same on either side of bead

Question 12

Peg

Answer 12

• dimensionless and fixed

- can be smooth or rough

Question 13

Air resistance

Answer 13

• usually modelled as being negligible

Question 14

Gravity

Answer 14

• uniform and acts vertically downwards

- g = 9.8

Question 15

4 vectors

Answer 15

Displacement - distance in a direction
Velocity - rate of change of displacement
Acceleration - rate of change of velocity
Force/weight - magnitude, direction and point of application