A vector is an arrow that represents the

magnitude and direction of a quantity.

• Force is an example of a vector because it

has an amount and a direction in which the

force is applied.

magnitude and direction of a quantity.

• Force is an example of a vector because it

has an amount and a direction in which the

force is applied.

What is a vector?

a force is a push or a pull. A force can cause an object to start to move to stop or to change direction.

Examples?

Examples?

What is a force?

A force where objects come into physical contact with each other and exert forces on each other

What is a contact force?

A force that does not have physical contact i.e. gravity, electrical charge, magnetic attraction

What is a field force?

it is the Newton (N). it can also be measured in other units like pounds.

What is the scientific unit of force?

The combination of all the forces acting on an object. If an object is not moving, can we conclude

that no external forces are acting on it? No, just that thenet force equals (sums to) zero!

that no external forces are acting on it? No, just that thenet force equals (sums to) zero!

What is a net force?

when they are moving at constant speed in a straight line path

When are moving objects in equilibrium?

no it can’t.

Can an object be in equilibrium if only one force acts on it?

Friction is a contact force between objects that slide against each other.

What is friction?

If the pushing force is equal to the friction force opposing it.

When is an object sliding along the floor in equilibrium?

when an object at equilibrium is at rest

What is static equilibrium?

an object that is moving.

What is dynamic equilibrium?

Yes! The object could move at a constant

speed. Nothing is causing a change in

velocity.

speed. Nothing is causing a change in

velocity.

Is it possible for an object to move if no net force is acting on it?

Tension is the upward force a rope or spring exerts on an

object hanging from it.

object hanging from it.

What is tension?

Weight is the gravitational force with which the object is attracted to the earth.

What is weight?

Is a state wherein no physical changes occur;

it is a state of steadiness.

• The net force on the object is zero.

• Mathematically this expressed as:

Sum of F =0

it is a state of steadiness.

• The net force on the object is zero.

• Mathematically this expressed as:

Sum of F =0

What is mechanical equilibrium?

The sum of two or more vectors is

called their resultant.

• Combining vectors is quite simple

when they are parallel:

– If they are in the same direction,

they add.

– If they are in opposite directions,

they subtract.

called their resultant.

• Combining vectors is quite simple

when they are parallel:

– If they are in the same direction,

they add.

– If they are in opposite directions,

they subtract.

What is called the sum of two or more vectors?

if they are in the same direction – they add

if they are in opposite directions – they subtract

if they are in opposite directions – they subtract

How do you combine vectors when they are parallel?

To find the resultant of nonparallel vectors, we use the

parallelogram rule.

• Consider two vectors at right angles to each other, The constructed parallelogram in this special case is a rectangle. The diagonal is the resultant R.

Example

parallelogram rule.

• Consider two vectors at right angles to each other, The constructed parallelogram in this special case is a rectangle. The diagonal is the resultant R.

Example

How do we find the resultant of non parallel vectors?

is the way we find the resultant of non parallel vectors.

What is the parallelogram rule?

In the special case of two perpendicular vectors that are

equal in magnitude, the parallelogram is a square.

The resultant is square root of 2 times one of the vectors.

For example, the resultant of two equal vectors of

magnitude 100 acting at a right angle to each other is

141.4 Example

equal in magnitude, the parallelogram is a square.

The resultant is square root of 2 times one of the vectors.

For example, the resultant of two equal vectors of

magnitude 100 acting at a right angle to each other is

141.4 Example

What is the resultant of two perpendicular vectors of the same magnitude?