P3.2 Flashcards
What is an object with a wide base and low centre of mass more stable than
Objects with a narrow base and a high centre of mass
What does not exist in its own right
Centripetal force
What is centripetal force always provided by
Something else such as gravitational force, friction or tension
What is the centre of mass of an object
The point at which mass the mass of the object may be thought to be concentrated
How do u find the centre of mass of a thin, irregular sheet of a material
Make a hole in one end
Put the card through a plum line
Suspend the card
Draw a line where the string goes across the card
Repeat this process and where both lines meet that is the centre of mass
What happens if u freely suspend an object
The object will come to rest with its centre of mass directly below the point of suspension
Where is the centre of mass of a symmetrical object
Along the axis of symmetry
What does the time period of a simple pendulum depend on
On the length of a pendulum
What is a moment
The turning effect of a force
What happens if an object is not turning
The total clockwise moment must be exactly balanced by the total anti-clockwise moment about any pivot
What will happen if the line of action of the weight of an object lies outside the base of the object ?
There will be a resultant moment and the body will tend to topple
What are virtually incompressible
Liquids
Why are liquids virtually incompressible
Because a force exerted or pressure at one point on a liquid will be transmitted to other points in the liquid
What enables a hydraulic system to be used as a force multiplier
The use of different cross-sectional areas on the effort and load side of a hydraulic system
What happens when an object moves in a circle
It continuously accelerates towards the centre of the circle and this acceleration changed the direction of motion of the body not its speed
