Centre Of Gravity Flashcards
1
Q
What’s the pivot?
A
A point to which the object is fixed but free to rotate around.
2
Q
What is the centre of mass?
A
The point of average mass of object.
3
Q
What is the centre of gravity?
A
The point though which the weight of the object acts
4
Q
In what situation does an objects centre of gravity differ from its centre of mass?
A
If the object is not in a uniform gravitational field
5
Q
What is true about the mass of all the particles on either side of the centre of mass(right/left, above/ below, infront of/behind)?
A
The mass of all the particles are equal on either side
6
Q
How do you find the centre of gravity of an irregularly-shaped piece of card?
A
- Set up as shown.
- Part of the fun is to design an irregular
shaped sheet of cardboard to test but it’s
important that the shape is not so irregular that the centre of gravity lies outside the
object. - Hang the sheet of cardboard from a pin so
that it is free to rotate. - Attach a weight to a piece of string and then fasten the free end of the string to the nail so that the weight hangs straight down.
- Draw a line to represent the position of the
string.
(hint: drawing a line while the cardboard sheet is hanging is tricky to do, so you could mark two points on the line, and then draw the line with the cardboard sheet removed and placed on a desk) - Repeat with the cardboard sheet suspended from a different hole.
- The intersection of the two lines represents the centre of gravity of the object.
- Now repeat one more time for a different orientation to verify that this line also goes through the same intersection
7
Q
State & explain 2 properties which increase the stability of an object.
A
- A low centre of mass - the lower the centre of mass, the mere an object can tilt before its centre of mass becomes offset from its base
- A wide base -if the centre of mass of an object doesn’t sit vertically above the base, the object is likely to pivot around the corner of the base & topple over
