Newton's First Law of Motion:
An object at rest will remain at rest unless acted on by an unbalanced force.
Newton’s first law explains why it takes extra force to get moving or to stop moving – seen through Static Force and Dynamic Force.
- Static Force: When a body is a rest, it wants to stay at rest and this must be overcome in order for fluid movement to take place. This can be noticed when pushing off the wall or the bottom of a pool. The drag that is felt when the movement starts is the static force that the swimmer is trying to overcome.
- Dynamic Force: Once a body is in motion, it wants to continue to stay in motion and is the reason that swimming becomes fluid after the initial movement. Once dynamic force is experience, the swimmer could just continue forever, however the drag will pull you to a stop eventually.
The swimmer will stay in motion unless acted upon by a force (water produces a resistive force that requires propulsive forces to overcome).
In essence for motion, Propulsive forces (thrust) > Resistive forces (drag).
Newton’s first law explains why it takes extra force to get moving or to stop moving – seen through Static Force and Dynamic Force.
- Static Force: When a body is a rest, it wants to stay at rest and this must be overcome in order for fluid movement to take place. This can be noticed when pushing off the wall or the bottom of a pool. The drag that is felt when the movement starts is the static force that the swimmer is trying to overcome.
- Dynamic Force: Once a body is in motion, it wants to continue to stay in motion and is the reason that swimming becomes fluid after the initial movement. Once dynamic force is experience, the swimmer could just continue forever, however the drag will pull you to a stop eventually.
The swimmer will stay in motion unless acted upon by a force (water produces a resistive force that requires propulsive forces to overcome).
In essence for motion, Propulsive forces (thrust) > Resistive forces (drag).
Newton's Second Law of Motion:
Force = mass x acceleration.
In swimming, the force produced by the swimmer is equal to the mass of the swimmer multiplied by the acceleration of the swimmer in the water. Newton’s second law can explain why some people swim faster than others. If we have two swimmers of the same weight and have them push off a wall and not take any strokes – the one who used the most force pushing off the wall would be the person who has travelled the furthest. Acceleration in this case was greater for the person who produced the greater force as both swimmers had the same mass.
Example: F = MA
Swimmers both have a weight of 80kg.
One takes off with an acceleration of 1m/s/s and the other takes off with an acceleration of 1.5m/s/s.
1. F = 80kg x 1m/s/s
F = 80N
2. F = 80kg x 1.5m/s/s
F = 120N
- If force is increased, then acceleration increases when mass is constant
- If mass is increased, then force increases when acceleration is constant
- If mass is increased, then acceleration decreases when force is constant
(all the above work the opposite way too!)
In swimming, the force produced by the swimmer is equal to the mass of the swimmer multiplied by the acceleration of the swimmer in the water. Newton’s second law can explain why some people swim faster than others. If we have two swimmers of the same weight and have them push off a wall and not take any strokes – the one who used the most force pushing off the wall would be the person who has travelled the furthest. Acceleration in this case was greater for the person who produced the greater force as both swimmers had the same mass.
Example: F = MA
Swimmers both have a weight of 80kg.
One takes off with an acceleration of 1m/s/s and the other takes off with an acceleration of 1.5m/s/s.
1. F = 80kg x 1m/s/s
F = 80N
2. F = 80kg x 1.5m/s/s
F = 120N
- If force is increased, then acceleration increases when mass is constant
- If mass is increased, then force increases when acceleration is constant
- If mass is increased, then acceleration decreases when force is constant
(all the above work the opposite way too!)
Newton's Third Law of Motion:
For every action there is an equal and opposite re-action.
In swimming, this can relate this concept to the standard hand/arm stroke when the hand travels downward in the water and then backwards to propel the swimmer forward. In creating an equal and opposite reaction, the swimmer is kept afloat and propelled forward.
In swimming, this can relate this concept to the standard hand/arm stroke when the hand travels downward in the water and then backwards to propel the swimmer forward. In creating an equal and opposite reaction, the swimmer is kept afloat and propelled forward.