Chapter 8 - Physics Flashcards
What is displacement?
The distance in a given direction.
What is a vector quantity?
A physical quantity which has magnitude and direction
What is a scalar quantity?
It has a magnitude but no direction
How can a vector quantity be represented?
It can be represented by an arrow in the direction of the vector and of length in proportion to the magnitude of the vector.
What can forces change?
They can change the shape of an object, or change it’s motion or it’s state of rest.
What is the unit of forces?
Newtons (N)
What is a contact force?
It is a force that acts on objects only when the objects touch each other
What happens when two objects interact?
They always exert equal and opposite forces on each other
What is the resultant force?
It is a single force that has the same effect as all the forces acting on an object.
What happens when a resultant force on an object is 0?
The object stays at rest or at the same speed and direction.
What happens when a resultant force on an object is greater than 0?
The speed or direction of the object will change
If two forces act on an object along the same line, what is their resultant force?
Their sum, if the forces act in the same direction.
Their difference, if the forces act in opposite direction.
What is the centre of mass?
The centre of mass of an object is the point where it’s mass can be thought of as being concentrated.
What happens when an object is freely suspended?
It comes to rest with it’s centre of mass directly underneath the point of suspension.
