Post on 06-Jan-2016
description
Resultant force
Resultant force : one force replacing the effect of several forces ( the force left over)
1. Zero Resultant force:
* Object remains stationary if it was at rest
Book on a table
weight
Reaction
Resultant force
Resultant force : one force replacing the effect of several forces ( the force left over)
1. Zero Resultant force:
* Object remains stationary if it was at rest
* Object continues to move at the same speed and in the same direction
Book on a table Moving marble on a smooth table
weight
Reaction
2 m/s
1. Zero Resultant force:
* Object remains stationary if it was at rest
* Object continues to move at the same speed and in the same direction
Car is going at full throttle and just stays at 70mph
1. Zero Resultant force:
* Object remains stationary if it was at rest
* Object continues to move at the same speed and in the same direction
DRAG = 60 KN THRUST = ?
Car is going at full throttle and just stays at 70mph
2. None zero resultant force:
* object will accelerate or decelerate
The plane accelerates at take off..
DRAG = 1 KN THRUST = 10 KN
2. None zero resultant force:
* object will accelerate or decelerate
The plane accelerates at take off..
...because thrust is larger than drag
DRAG = 1 KN THRUST = 10 KN
2. None zero resultant force:
* object will accelerate or decelerate
The plane accelerates at take off..
...because thrust is larger than drag
DRAG = 1 KN
When flying at constant speed at constant height thrust is greater than / equals / is less than drag.
THRUST = 10 KN
RESULTANT or UNBALANCED FORCES
RESULTANT or UNBALANCED FORCESRESULTANT or UNBALANCED FORCES
RESULTANT or UNBALANCED FORCESRESULTANT or UNBALANCED FORCES
RESULTANT or UNBALANCED FORCESRESULTANT or UNBALANCED FORCES
RESULTANT or UNBALANCED FORCES
Object at the start
at rest
Resultant force Effect on the speed
moving
zero
zero
?
?
Object at the start
at rest
Resultant force Effect on the speed
moving
zero
zero
stays at rest
?
Object at the start
at rest
Resultant force Effect on the speed
moving
zero
zero
stays at rest
Velocity stays the same
Object at the start
at rest
Resultant force Effect on the speed
moving
moving
moving
zero
zero
Non zero in the same directionas the moving object
Non zero in the opposite direction
as the moving object
stays at rest
Velocity stays the same
?
?
Object at the start
at rest
Resultant force Effect on the speed
moving
moving
moving
zero
zero
Non zero in the same directionas the moving object
Non zero in the opposite direction
as the moving object
stays at rest
Velocity stays the same
accelerates
?
Object at the start
at rest
Resultant force Effect on the speed
moving
moving
moving
zero
zero
Non zero in the same directionas the moving object
Non zero in the opposite direction
as the moving object
stays at rest
Velocity stays the same
accelerates
decelerates