P8 Forces in Balance

Properties of scalar quantities

Have magnitude only

Properties of vector quantities

Have direction and magnitude

How do you represent a vector on a drawing?

An arrow. The length of the arrow represents magnitude, the direction of the arrow represents the direction of the vector quantity

What is a force?

A push or pull that actos on an object due to the interaction with another object

What are contact forces?

When the objects are physically touching

What are non-contact forces?

When the objects aren’t physically touching

Examples of contact forces

Friction, air resistance, tension, normal contact force

Examples of non-contact forces

Gravitational force, electrostatic forces magnetic force

Is force a scalar or vector quantity?

Vector

Define resultant force

A number of forces acting on an object may be replaced by a single force that has the same effect as all the original forces acting together

Newtons first law

if the resultant force acting on an object is zero and the object is stationary, it remains stationary. If the object is moving, it continues to move at a constant speed in the same direction

What happens to the resistive forces if a vehicle travels at a steady speed

The resistive forces will balance the driving forces

When will the velocity of an object change?

If a resultant force is acting on the object

What is inertia?

The tendency of objects to continue in their state of rest or of uniform motion

Newtons third law

Whenever two objects interact, the forces they exert on each other are equal and opposite.

What is referred to if the weight of an object may be considered to act at a single point in an object?

The centre of mass