4.1+ 4.2 Force, Mass, Center of Mass Flashcards
1
Q
resultant force rules
A
- RF not required for motion
- RF is required for acceleration
- constant velocity means no RF
2
Q
what is mass?
A
measure of inertia (resistance to a change in velocity)
3
Q
what is weight?
A
that force of attraction that acts on a body (due to mass and gravitational field interaction)
4
Q
what is the centre of mass?
A
- a single point at which the body’s mass can be thought to be concentrated
- basically used to simplify calculations
point of weight acting down
5
Q
where does the centre of mass lie?
A level Questions
A
where all lines of symmetry cross
6
Q
how can the centre of mass be found for a realistic body?
A
- suspend the body from a position near the edge
- allow it to come to rest
- draw a line vertically down, using a plumb line to guide
- suspending from another point
- rest, vertical line staight line
- centre of mass lines where the two lines cross
when at rest weight acts through CofM, giving rise to 0 moment
