Newton's Laws Of Motion Flashcards
What is inertia?
An objects tendency to remain in a steady state such as at rest or moving straight forward at a constant speed
What is Newton’s First Law?
Velocity, speed and direction of an object will only change if a resultant force is acting on it
Velocity changes when the resultant force is not 0, otherwise the object will remain constant
In a car, driving forces must be equal to resistive forces for a constant speed
What is momentum?
Vector quantity which depends on mass and velocity and is a property of all moving objects
Momentum = mass x velocity
What is Newton’s Second Law?
The acceleration of an object is
Proportional to the resultant force
Inversely proportional to the mass of the object
Resultant force = mass x acceleration
What is inertial mass?
How difficult it is to change the velocity of an object
Inertial mass = force/ acceleration
What is the Law of Conservation of Momentum?
In a closed system total momentum before an event is equal to the total momentum after the event
If two moving objects collide
m1u1 + m2u2 = m1v1 + m2v2
m = mass
u = initial velocity
v = final velocity
Why is momentum in explosions conserved?
The total momentum before is zero
After the total momentum is also zero as the different objects travel in different directions and so the momentum of each part will cancel out
What happens if two moving objects recoil?
They start off with a total momentum of zero and end up moving away from each other
m1v1 + m2v2 = 0
What is Newton’s Third Law ?
Whenever two forces interact with each other, they exert equal and opposite forces. Forces always occur in pairs and each force acts on separate objects, are the same size and occur in opposite directions along the same line and are of the same type
