physiks Flashcards
Newton’s 1st law of motion
Object in rest remains in rest, or if in motion, remains in motion, unless there is a resultant(net) force.
Newton’s 2nd law of motion
Motion(momentum) is directly proportional to the force acting on it.
F = ma (F=dp/dt = m×dv/dt = ma)
Newton’s 3rd law of motion
For every action, there is always an equal reaction to the opposite direction on the object who acts the force.
Kinetics(dynamics)
Branch of physics dealing with relationship between force and motion(effect of forces on the motion of objects)
Field
A region in which each point has a physical quantity associated in it(could be scalar or vector)
Force
Influence that can cause an object to change its velocity.
Types of forces
Elastic
Frictional
Contact/normal
Gravitational
Types of contact forces
Friction
Fluid resistance/vicous drag
Tension
Normal(reaction) force
Non-contact force
Gravitational
Electrostatic
Magnetic
Equilibrium
All forces are balanced - resultant force is 0
Types of friction
Static friction - the object is stationary on a surface
Dynamic friction - the object is moving on a surface
Torque - moment
A force which causes change in rotational speed(circular motion/angular velocity)
Moments must be balanced or the object will turn
Newtonmeter/Nm
Pivot - os otáčania
Inertia
Natural tendency of objects in motion/rest to remain in motion/rest
Principle of inertia - Newton’s 1st law
Momentum
Product of mass and velocity
Momentum is always conserved, just like energy
Momentum before = momentum after
Impulse(J)
Newton’s second/Ns
Product of force applied and time for which it acts
J=F∆t(J=∫Fdt)=∆p=mv-mu
Change in momentum is equal to Impulse
