Mechanics random qs

Question 1

state the modelling assumptions of calling an object a particle

Answer 1

• weight acts from centre of mass
• ignore effects of air resistance and rotational forces
• has no dimensions
• smaller in comparison to other sizes and lengths

Question 2

state the modelling assumptions of a rod

Answer 2

• mass distibuted along a line ( it is roughly one dimensional)
• rigid

Question 3

state the modelling assumptions of a lamina

Answer 3

• weight distibuted across a flat surface
• no thickness

Question 4

state the modelling assumptions of a uniform body

Answer 4

• mass is evenly distributed across the entire volume of the body
• has a centre of mass (the point where the mass is concentrated)

Question 5

state the modelling assumptions of an inextensible string in a pulley

Answer 5

• acceleration is the same in the objects on either side of pulley

Question 6

state the modelling assumptions of a smooth pulley and light string

Answer 6

• tension is the same throughout the string

Question 7

state modelling assumptions of light horizontal rod

Answer 7

rod has no mass = rod has no weight

tension same throughout entire length of rod