Com And Equilibrium

Question 1

What’s the difference between com and cog

Answer 1

Com- distribution of mass in a direction, Not dependent on gravitational field

Cog - distribution of weight in all directions

Question 2

What is gravity and what does it depend on

Answer 2

A force acting between masses

• it is always attractive and depends on the masses involved and their separation

F = force
C= constant
M = mass
R = separation of masses

Question 3

What is equilibrium

Answer 3

• sum of force son a body is zero
• sum of moments about a point = 0

Question 4

What is moment about an axis

Answer 4

Moment about an axis (or torque) is a product of the force and perpendicular distance from the line of action of force to the pivot point

Force x perpendicular distance

M(nm) = fd

Question 5

What equipment is used to measure cog

Answer 5

Statograph - sums moments about an axis

Reaction board - sums moments about 2 axis