3.5 Newton’s Laws of Motion Flashcards
Newton’s first law
An object will remain at rest of move at a constant velocity unless acted upon by a resultant force
Newton’s second law of motion
Resultant force acting on an object is proportional to its rate of change of momentum, and is in the same direction.
Newton’s third law of motion?
When two objects interact they exert forces on each other that are equal in magnitude, opposite in direction and of the same type of force.
What two sets of units can be used for momentum?
Ns OR kgms^−1
How is the momentum of an object calculated?
Mass × velocity (p=mv)
What is the principle of conservation of momentum?
The total momentum in a system of interacting objects is constant provided no external force acts.
What is an elastic collision?
A collision in which kinetic energy is conserved
What is an inelastic collision?
A collision in which some kinetic energy is transferred to other forms
How is impulse calculated?
Force x time
What is the relationship between impulse and momentum?
Impulse is equal to the change in momentum
What is represented by the area under a force time graph
Impulse
What is represented by the gradient of a momentum-time graph?
Resultant force
What is the change in momentum when an object of momentum p collides elastically at right angles with a wall?
-2p
When can F=ma be used?
When an object has constant mass
