Ch8 Modelling in mechanics

Question 1

Particle

Answer 1

mass of object concentrated at single point

rotational forces and air resistance can be ignored

Question 2

rod

Answer 2

mass is concentrated along a line

no thickness

rigid

Question 3

lamina

Answer 3

mass is distributed across flat surface

Question 4

uniform body

Answer 4

mass is concentrated at single point at centre of body

Question 5

light object

Answer 5

has 0 mass
tension is the same at both ends of light string

Question 6

inextensible string

Answer 6

acceleration is the same in objects connected by string

Question 7

smooth surface

Answer 7

assume there is no friction between surface and object

Question 8

rough surface

Answer 8

objects in contact with surface experience frictional force if moving

Question 9

wire

Answer 9

one dimensional

Question 10

smooth and light pulley

Answer 10

has no mass
tension is same of either side of 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

Question 13

Gravity

Answer 13

9.8ms-2