Forces Flashcards
Newton’s 1st law
A body stays at rest or continues to move with a constant speed in a straight line unless acted upon by a net external force.
Newton’s 2nd law
The rate of change of linear momentum of a body is directly proportional to the resultant force acting on it and occurs in the direction of the force
Newton’s 3rd law
If body A exerts a force on body B, then body B will exert an equal and opposite force on body A
Linear momentum
Linear momentum of a body is the product of its mad and its velocity.
Impulse
The impulse of a force is the product of the average force and the time interval over which it is applied
Impulse-momentum theorem
The change in momentum of a particle during a time interval equals the impulse of the net force that acts on the particle during that interval
1 Newton
The amount of force that gives an acceleration of 1ms^-2 to a body with a mass of one kilogram
Principle of conservation of linear momentum
The total linear momentum of a system is conserved if no external force acts on the system
Head-on collision
One in which the directions of motion before and after the collision are along the same line of motion
Elastic collisions
KE is conserved, relative speed of approach = relative speed of separation
Inelastic collisions
KE not conserved
Perfectly inelastic collision
2 objects stick together and move with constant velocity. This represents the maximum possible loss of KE without violating the PCOE
Hooke’s law
The extension of a spring is proportional to the load if the limit of proportionality is not exceeded
Upthrust
The upward force acting on an object that is partially or fully immersed in a fluid, due to differences in pressure acting on the top and bottom face
Couple
Consists of a pair of parallel forces of equal magnitude but opposite direction whose line of action do not coincide.
