CH7 Flashcards
If an object is in equilibrium it means the object is …
Not accelerating; it is either:
● Stationary
● Moving at a constant velocity
What does Newton third law state?
When two objects interact they exert equal and opposite forces on each other
What is Newton’s second law?
F = ma
The resultant force of an object is proportional to the rate of change of momentum of the object and in the same direction.
What is Newton’s first law?
An object at rest or moving with constant velocity will stay that way unless a resultant force acts upon it.
What does need to change for an object’s velocity to change?
Velocity of an object changes if its speed and/or direction change. This is becausue velocity is a vector quantity
Give an equation that can be used to calculate
momentum.
momentum = mass × velocity
What is the SI unit of momentum?
Kgms-1
What type of quantity is momentum?
It is a vector quantity because it is the product of mass (scalar) and velocity (vector)
State the principle of conservation of momentum
For a system of interacting objects the total momentum in a specified direction remains constant, as long as no external forces act on the system
What happens to the total momentum when objects collide?
The total momentum before and after the collision stays the same
