Newton’s Laws of Motion
Newton’s First Law
· An object either remains at rest or keeps travelling at constant velocity provided no resultant force acts.
Newton’s Second Law
· The net force acting on an object is equal to the rate of change of the linear momentum of an object. (F=ma is just a special case where m is constant)
Linear Momentum () = mass of an object (m) x velocity (v)
Net Force on a body is the rate of change of momentum
(N or kgms-2) - Net Force
- Change in Momentum
- Change in Time
Newton’s Third Law
· When two objects interact, the forces they exert on each other are equal in magnitude and opposite in direction.
Impulse (Ns or kgms-1) = force x change in time = Change in Momentum
In a force against time graph, the area underneath in the impulse
Principle of Conservation of Momentum
· The total momentum before a collision = the momentum after a collision, provided no external forces act
Elastic and Inelastic Collisions
· In an elastic collision, the total kinetic energy of the system remains constant. Momentum and total energy are conserved.
· In an inelastic collision, the total kinetic energy in not conserved. Some of the KE is transformed into heat, sound, etc. Momentum and total energy is conserved.
· A total inelastic collision is when the two bodies stick together and they move off with the same velocity
Period (T) is the time it takes for an object to make a complete orbit around its circular path.
Circumference of a Circle is radians
The Angular Displacement of a body is the angle in radians through which a point has been rotated.
s - Arc length
r - Radius
One Radian is when the Arc Length is equal to the radius
Degrees --> Radians
Radians --> Degrees
t is for time
· Is the rate at which the object’s angular displacement changes (the rate at which it is going around the circle)
Definition – Moving or trending towards a centre.
Centripetal Acceleration (a)
An object moving along a circular path has a changing velocity, even if its speed is constant. It is being accelerated towards the centre of the circle.
A force that acts on a body moving in a circular path and is directed toward the centre around which the body is moving
Using the equation we get:
Newton’s Law of Gravitation
· This law states that any two bodies attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them
F - The force due to the gravitational attraction between the two objects (N)
G – The Gravitational Constant
M – Mass of the…