5.1 Forces & Their Interactions

What is a scalar quantity?

Quantity that only has magnitude

What is a vector quantity?

Quantity that magnitude and direction

When representing a vector, what does the length of the arrow represent?

magnitude

When representing a vector, what does the direction of the arrow represent?

direction

What is a force?

Push or pull that acts on an object due to interaction with another object

What is a contact force?

Force that acts on 2 objects that are physically touching

What is a non-contact force?

Force that acts between 2 objects that are physically separated

What are 4 examples of contact forces?

• Friction

• Air Resistance

• Normal Contact Force

• Tension

What are 3 examples of non-contact forces?

• Gravitational force

• Electrostatic force

• Magnetic force

Is force a scalar or vector quantity?

Vector

What is weight?

Force acting on object due to gravity

What is the force of gravity close to the Earth due to?

Gravitational field around Earth

What does the weight of an object depend on?

Gravitational field strength at point where object is

What is the equation for calculating the weight of an object?

$$W = mg$$

What is meant by ‘centre of mass’?

Single point where weight of an object acts

The weight of an object and the mass of an object are ___________ ______________.

directly proportional

What do you use to measure weight?

Newtonmeter

What is a resultant force?

Single force that replaces a number of forces acting on an object — has the same effect as original forces

What can a single force be resolved into?

Two components acting at right angles to each other — have the same effect as single force

An object at rest experiences a __________ ________.

reaction force

An object that is being stretched experiences a ________ _______.

tension force

Two objects sliding past each other experience __________ ________.

friction forces

An object moving through the air experiences ___ ___________.

air resistance

What is a magnetic force experienced by?

Magnetic material in a magnetic field

What is an electrostatic force experienced by?

Charged particle in an electric field

What is a gravitational force experienced by?

Mass in a gravitational field

All objects with mass produce a ____________ _____.

gravitational field

The more mass an object has, the greater its ____________ _____ will be.

gravitational field