Transcript Newton`s Laws

PE - Biomechanics
Learning Objectives…
To understand Newton's laws
To be able to link Newton’s laws to sporting
examples.
To understand the application of forces
Newton’s First Law of Motion
A body continues in a state of rest or uniform velocity
unless acted upon by an external force.
Sporting Examples:
 “ A football will stay on the penalty spot until kicked”
 “A hockey ball will remain still until hit by the stick”
 “ A football will roll until slowed by friction or another player”
 “ A hockey ball will not fall from the air without the
application of gravity”
Newton’s First Law of Motion
A body continues in a state of rest or uniform velocity
unless acted upon by an external force.
Newton’s First Law of Motion
A body continues in a state of rest or uniform velocity
unless acted upon by an external force.
PUSH or PULLS can alter a body (object) in the following ways
•Cause a body to move (as seen in the previous slide)
•Cause a body to accelerate
•Cause a body to decelerate
•Cause a body to change direction
•Cause a body to change shape
Forces Can Cause a body to accelerate
Sporting example: Sailing boat.
The force that causes the boat to acceleration is the wind.
Forces Can Cause a body to decelerate
Sporting example: Sailing boat.
The force that causes the boat to deceleration is the wind.
Forces Can Cause a body to change direction
Sporting example: Tennis
The force that causes the Ball to change
direction is the racket impact.
Forces Can -
Ball shape is compressed
by the force of the club
head on impact
Cause a body to change shape
Sporting example: Golf
The force that causes the ball to change shape is the impact from the
club head.
Newton’s Second Law of Motion
When a force acts on an object, the motion
experienced by the object is proportional to the size
of the force and in the direction in which it is applied.
Sporting Examples:
 “If you kick a football hard, it will go a long way”
 “If you kick a football softly it wont go very far”
 “If you hit a hockey ball to the left, it will go left”
 “If you hit a hockey ball to the right, it will go right”
Newton’s Third Law of Motion
For every action there is an equal and opposite
reaction.
Sporting Examples:
 “If a rugby player pushes to the left with their foot, they
swerve to the right.”
 “A high jumper needs to push down on the ground to be able
to go up.”
 A football goalkeeper needs to push to the left with their feet
in order to dive to the right.”
Reaction force is the goal
keeper lifting into the air in
the opposite direction
Action force is the goal keeper
pushing down into the floor