Download Balanced and Unbalanced Forces

Balanced and Unbalanced
Forces
Force
• A force is a push or pull that causes an object to
move, stop, or change direction
• Has a size and a direction
• In physics a force is anything that makes an
object accelerate (remember: acceleration in
science can mean speed up, slow down, change
direction or change speed & direction!)
How do we measure force?
• A spring scale is used to measure force.
• The units of measurement for force, are called
Newton.
Mass Vs. Weight
• Mass is the amount of matter in an object.
• The tool we use to measure mass is the Triple
beam balance.
• The units used to measure mass are grams (g).
• Weight is the measure of gravitational force on an
object.
• The tool we use to measure weight is the spring
scale.
• The unit for weight is the gram (g).
Balanced and Unbalanced Forces
• Forces occur in pairs and they can be
either balanced or unbalanced.
Balanced Forces
• Balanced forces do not cause change
in motion
• They are equal in size and opposite
in direction
Examples of Balanced
Forces
Unbalanced Forces
• Unbalanced forces are NOT equal in size.
• An unbalanced force always causes a
change in motion! This can be a change in
speed, direction or both.
• When unbalanced forces act in opposite
directions you can find the net force. To
find the net force, you
• Calculate the Magnitude of the force. This is the
difference between the two forces, so you subtract the
smaller force from the larger one.
• Determine the direction of the net force. The direction
of the largest force is the direction of the force (IF they are
going in opposite).
Examples of Unbalanced
Forces
Unbalanced Forces
3 N, right – 6 N, left = 3N, left
Unbalanced Forces
4 N, left – 10 N, right =
6N, right
Unbalanced Forces
5 N, right + 10 N, right =
15N, right
Balanced or Unbalanced Forces?
Types of Forces
• Gravitional Force (Gravity) – is the force of
attraction between objects due to their
masses.
• Friction – the force that exists when there
is contact between 2 surfaces (It opposes
motion)
• Applied force – force that is applied to an
object by a person or another object.
Types of Forces (continued)
• Net force – the combined effect of all
forces acting on an object.
• Balanced – Forces are balanced when they
act on an object in opposite directions and
are equal in size (no change in the
position, speed, or direction of motion of
the object).
• Unbalanced – opposing forces that are not
equal (causes change in position,
direction, or speed).