A force is a push or pull that can be described by its strength and direction. Forces are measured in Newtons. A net force is the combination of all individual forces acting on an object, determining its speed and direction of motion. Unbalanced forces produce a net force causing motion, while balanced equal forces in opposite directions produce no net force and no change in motion.

1. Daily Science
1.What is a force?
2. What is the difference
between a balance and
unbalanced force?

2. What is a Force?
• A force is described by its
strength and by the direction in
which it acts.
• A force is either a push or a pull
• A force’s SI unit is called Newton.
• Why is it called a Newton?

3. Combining Forces
• What do you think it means when
a force is combined?
• A Combination of forces acting on
an object is called a net force.
• A net force determines an objects
speed and direction.

4. When forces act in the same
direction the forces can be added
together:
5 5 10 N

5. • When forces act in an
opposite direction they also
combine a net force.
• If one force is going in one
direction and another force
in the opposite direction all
you do is subtract the
forces.

6. • Example:
5N 10N = 5N
Forces may even cancel each other out:
5N 5N = 0N

7. Unbalanced Forces
• When there is a net force
acting on an object, the forces
are unbalanced.
• This causes the object to
move.

8. • Example’s of Unbalanced
forces:
Individual
Forces
Net Force
Individual Forces
Net Force

9. Balanced Forces
• Equal forces acting on one
object in opposite directions
are called balanced forces.
• The object’s motion does
not change.

10. Example of a balance force:
No Net Force

11. Any Questions?