Dynamics-Forces Flashcards
What is Newton’s first law?
An object will remain in a state of at rest or uniform motion in a straight line unless acted upon by an external force
Change of state of motion
What is Newton’s second law?
For an object with constant mess, the net external force acting on the object = the product of its mass, m and acceleration a.
F=ma
What is Newton’s third law?
For every action, there is an equal and opposite reaction
Paired forces
What are the conditions for an action-reaction pair?
Same magnitude
Same nature/type
Acting on Different body
Acting in Opposite direction
What are the different types of contact forces?
-Normal force (N): Contact force perpendicular to surface of contact
-Frictional force (F): Force that opposes motion between two objects, direction of force always parallel to surface of contact
-Tension (T): Pulling force exerted by a string when taut, direction always parallel to string
-Resistance: Frictional force experienced by an object moving through air or fluids, opposes direction of motion of object
What are the different types of non-contact forces
-Weight (W): Gravitational pull W=mg
-Magnetic force: The push or pull between two magnets
-Electric force: The push or pull between two magnets
What are the 3Is to take note of when doing Free body diagram?
Isolate the object
Identify the forces
Illustrate the forces
What factors affect friction?
1.The reaction force acting on the object due to other surfaces
2.The type of surfaces that are in contact with each other (The rougher the surface the greater the friction)
What are the types of friction?
Static frictional force: Frictional force experienced by a stationary object. Magnitude is equal to applied force and increases until it reaches maximal frictional force.
Dynamic frictional force: Frictional force experienced by moving objects. Magnitude is constant regardless of applied force and velocity and is maximum
