Module 3.5 - Newton's Laws of Motion Flashcards
State Newton’s first law of motion
A body will remain at rest or constant velocity until an external force acts upon it.
State Newton’s second law of motion
The resultant force on a object is proportional to the rate of change of momentum. A force causes an acceleration.
F = ma
State Newton’s third law of motion
If object A exerts a force on object B, then object B will exert a force an equal and opposite force on object A.
How is momentum calculated?
P = mv
Describe momentum
> units: kg ms^-1
Vector quantity
directly proportional to mass and velocity
How do you work out the net force using momentum?
F = ∆p ÷ ∆t
Define impulse
Change in momentum = F∆t
How is impulse worked out on a force-time graph?
Area under the graph
What is an elastic collision?
When momentum and the kinetic energy are conserved - no energy transferred to other forms such as heat and sound
What is an inelastic collision?
When the momentum is conserved but some kinetic energy is transferred to other forms in the collision.
How is momentum and kinetic energy related?
Momentum = mass x velocity
Kinetic energy = 1/2 x mass x velocity^2
Kinetic energy = 1/2 x velocity x momentum
State the principle of conservation of momentum
Total momentum before a collision is always equal to the total momentum after a collision.
