ASSUMPTIONS TO STATE

Question 1

Uniform mass distribution

Answer 1

For everyhting state so you can take centre of mass etc

This means the centre of mass is where line of symmetry occurd

Question 2

Assumption of smooth surfaces, pulleys,

Answer 2

No friction here so resultant force notaffected

Question 3

Assumption no air resistance when converting between gravity and kinetic energy

Answer 3

Works is conserved

Question 4

With upthrusg if some of the air is above the surface then

WHY SO WE ASSUME IT DOESNF

Answer 4

There is also force form air resistance sect i g down maybe, assume not

because th density kf the air is much less than density if water