Motion Flashcards
Friction, Lift, Projectiles
Define Friction
A force that acts in the opposes the direction of motion
Define Lift
A force which acts perpendicular to oncoming flow direction of the fluid acting on the body
Define Projectile
Any object that has been propelled into the air by a force and has no means of self-propulsion
Principles of Projectile Motion
1) Acceleration of the projectile is equal to the acceleration due to gravity, which always acts downwards
2) Horizontal motion of a projectile is constant since the only force acting is gravity (which acts downwards)
3) Vertical and Horizontal motion are independent of each other
What is Newton’s first law?
An object will either stay at rest or move with constant velocity unless acting upon by an external net force. (When the resultant force isn’t 0)
What is Newton’s second law
The net force acting on an object is directly proportional to its rate of change of momentum and is in the same direction.
When mass is constant: F=ma
What is Newton’s third law?
If an object exerts a force, there will be an equal and opposite force exerted on that object.
Or
If object A exerts a force on object B, The B will exert an equal but opposite force on A
Define Momentum
The product of an object’s mass and its velocity:
p=mv
What is the Conservation of Momentum
For a closed system, the total momentum before a collision is the same as the total momentum after, as long as no external force acts on the system.
(The total momentum in a given direction is conserved given no external force acts on the system)
What does the area under a force time graph represent?
The impulse
Or
The change in momentum
Define Impluse
The impulse acting on an object is equal to the change in momentum of that object
What is an Elastic collision?
A collision where the kinetic energy is conserved during a collision
What is an inelastic collision?
A collision where the kinetic energy is not conserved during the collision
